Astrid and Hiccup's Relationship

"Astrid, you and I have been through everything together. You don't think we can handle this? Astrid, you have me, no matter what. Okay, whatever that means, whatever you want it to mean. I am with you. There will always be a Hiccup and Astrid. Always."

- Hiccup to Astrid who is temporarily blind

Astrid and Hiccup's relationship throughout most of the franchise would best be termed as not always platonic best friends.

Hiccup Haddock has had a crush on Astrid Hofferson from a very young age. However, his awkwardness lands him in a more passive position in most of the development of their relationship. Astrid's feelings for Hiccup usually manifest themselves as extreme devotion and protectiveness, as she is always the first to aid him in any situation and the last to leave him, which Hiccup reciprocates towards Astrid. She was the last to leave him on his search for new dragons before Dagur broke out of prison and they moved to the Edge. It appears to be an unspoken assumption that Astrid will accompany Hiccup on his adventures, more so than the other Vikings, and will usually invite herself along regardless. On the rare occasions that they are separated by mitigating circumstances, Astrid is shown to worry greatly about Hiccup and is always overjoyed to be reunited with him. Beyond the romantic elements of their relationship, Astrid and Hiccup are the closest human friends that either of them has.

How to Train Your Dragon
At first, Astrid appears to be disinterested in Hiccup. She considers him irresponsible when he tries to go against higher orders to prove himself and is particularly unimpressed with his inability to stay focused in the training arena. Unlike the rest of her peers, Astrid never ridicules Hiccup or laughs at him but as he walked past the other teens, she stopped sharpening her axe to stare at him with curiosity.

Her vendetta against him seems to be on more personal ground and is fueled by suspicion and jealousy. Astrid grows particularly annoyed with him when he takes the upper hand during "dragon training", suddenly showing far superior skills than she could ever hope to achieve despite all her hard work and determination. She also seems to be the only one able to see through the facade Hiccup puts up in the wake of his popularity. By the time Hiccup takes the final win, Astrid has grown beyond aggravated.

Instead of confronting him calmly like she initially did when questioning him about his weirdness, Astrid follows him to the Cove and aggressively tries to press the truth out of him. When she hears something she throws Hiccup to the ground and moves forward to investigate. Once she spots Toothless, however, her feud with Hiccup is forgotten and her first instincts are to protect him from the dragon. Notably, it's not the first time Astrid warns Hiccup as she told him to get down and out of sight when facing danger during their training sessions. This time around, however, she physically attempts to protect him by pulling him to the ground with her. Hiccup is quick to intervene before anything serious happens. He attempts to calm both individuals down and explain himself to Astrid, who is thoroughly astonished by the revelation. Although it is unknown if she was actually running to the village, Astrid runs away in shock and fear, only to be picked up by Toothless and dropped in a tree.

After finally agreeing with Hiccup to "let him show her" why Toothless is not as dangerous as she believes, (having no choice other than fall out of the tree to her death) she reluctantly gets on the dragon. But sensing her attitude, Toothless doesn't listen to Hiccup's instructions to get down gently. Instead he races down, dunking his riders into the water, and spinning in circles. Astrid wraps both her arms and legs around Hiccup in fear, indicating she must have some trust in him. Astrid apologizes, and Toothless slows down, and she admires the beauty of the sky, especially as the sun starts to go down. She waves her hand through the clouds and even falls back so she can feel the wind in her hair. As they approach Berk, Astrid puts her arms around Hiccup's waist and leans her head on his shoulder, to Hiccup's surprise and then delight. As they go back into the air, she admits flying is amazing, and adding onto to it by saying Toothless is amazing.

As they try to go back, Toothless suddenly hears a call and flies into line with a ton of other dragons, Hiccup telling Astrid to get down so they aren't spotted. Once they are in the Dragon's Nest, Hiccup urges Toothless to get out for his and Astrid's safety, both Hiccup and Astrid slightly frightened when a Gronckle fails to get enough food for the Red Death and is promptly eaten. In horror, Astrid wraps her arms tightly around Hiccup's chest. Once escaping the Nest, Astrid immediately tells Hiccup they have to tell Stoick, but Hiccup gently takes her arm, telling her no, that they'll kill Toothless if the village finds out. She asks if he's really being serious about wanting to keep the Dragon's Nest a secret, as it's something Vikings have searched for since they first arrived, just to protect his pet dragon. When Hiccup firmly says yes, her face changes and shoulders drop, realizing just how important Toothless is to him. She decides to support him, asking what he's going to do, to which he says he'll think of something by the next morning. She then punches him in the arm, saying that's for kidnapping her. As he rubs his sore arm, she grabs him by the shirt and quickly kisses his cheek, stuttering slightly as she says that was for everything else before running back home, leaving Hiccup in shock and bewilderment, and embarassed in front of Toothless.

In the Arena the next day, she meets with him before he goes inside, gently asking what his plan is. He says he has to try to stop this, but if something goes wrong he asks her to take care of Toothless. She accepts, before asking him to promise her nothing will go wrong. He doesn't get the time to respond, as Gobber tells him it's time to go in. After trying to train the Monstrous Nightmare and Stoick angering it by losing his temper, Astrid cries out for Hiccup, using a nearby axe to force the arena door open and then throwing a hammer at the dragon to distract it from Hiccup. She continues trying to distract the dragon so Hiccup can get away until Stoick enters the arena and Toothless is subdued. Astrid then holds Hiccup back as he's desperately trying to stop his father and the other Vikings from chaining Toothless up.

After Toothless is locked up on a ship heading towards the Dragon's Nest, Hiccup watches them sail off in despair, and Astrid doesn't make him feel better when she states the obvious (he's lost his tribe, father, and best friend) but slowly turns it into an almost pep talk/motivational speech. She asks him why he didn't go through with his plan to kill Toothless when he found him in the woods, and he eventually confides in her that he saw himself when he looked at him. She asks him what he plans to do and he responds with "I don't know, probably something stupid" when she tells him it's a good start but he's already done that, he responds with "then something crazy".

When Hiccup introduces the dragons in the arena to the other Viking teens, she shows her support (probably being the main reason the other teens go in the first place), and when Ruffnut tries to flirt with Hiccup, Astrid pulls her away by her helmet. She makes sure the other teens are supportive as well.

During the battle against the Red Death, Hiccup and Astrid both ride Stormfly, Hiccup finding his confidence and calling out instructions to the other teens. He leaves her to fly the Dragon alone when he jumps down to free Toothless from a burning ship. He later saves Astrid when the Red Death tries to suck Stormfly into it's mouth and swallow her, before Hiccup has Toothless shoot a plasma blast at the Red Death, Astrid starts to fall to the ground before Toothless grabs her. She smiles up at Toothless and Hiccup before Toothless gently drops her on the ground. There she, Stoick, and the other Vikings watch in horror and awe as Hiccup and Toothless fight the Red Death in the clouds above. After Hiccup disappears in the smoke and fire, Astrid rushes to the scene, believing Hiccup is dead. Tears come to her eyes, and when she hears Stoick proclaim that he's still alive, even more tears come to her eyes as she rejoices with the Vikings.

After he wakes up and goes outside she sneaks up behind him and punches his back, claiming that was for scaring her. As Hiccup protests angrily, she smiles and pulls him forward for a real kiss on the lips. He quickly tells her he can get used to the punches as she blushes. She then joins Hiccup and the other teens for a dragon ride on their dragons as the movie ends, concluding their relationship as "not-always-platonic-best-friends".

It is possible that Astrid had feelings for Hiccup before the events in the movie, due to her immediate change in behavior during the first flight; she may have simply ignored them due to Hiccup not meeting the usual Viking standards. This is hinted at during the deleted scene 'An Axe To Grind', where she interacts with Hiccup amicably in Gobber's smithy (and does not dismiss him shooting down a Night Fury as impossible, unlike the majority of the tribe). In addition, when Hiccup was thought to be dead after he defeated the Red Death, Astrid is the only Viking to be brought to tears, meaning she took it the hardest, besides Stoick.

Legend of the Boneknapper Dragon
When Hiccup is upset for Gobber, Astrid takes a few steps closer to him perhaps to comfort him. When they are on the boat, Hiccup and Astrid sit next to each other, and while they are stranded on the island they are often standing next to each other. At Gobber's outrageous stories, and all the teens' annoyance at them, Astrid shoves Hiccup in Gobber's direction as a hint that he put a stop to this, indicating that Astrid trusts Hiccup to bring some sense to their situation.

Book of Dragons
Astrid and Hiccup are sharing a bench at a table in the Great Hall and sitting very close together.

Gift of the Night Fury
Astrid remains a close friend of Hiccup in Gift of the Night Fury, as Astrid and Hiccup both advocate the idea to make up new holiday traditions to cheer the tribe up. She gestures for some support in her ideas, and he's quick to give it. When the other teens didn't like her Yaknog, she says she bets that Hiccup would like it as she runs off to share it with him. As they discuss the prosthetic Hiccup makes for Toothless so the Night Fury can fly on his own, he also calls her "M'lady" as she hands him a cup of Yak-nog. Near the end of the special, Astrid comforts Hiccup when he's missing Toothless, holding his hand, lifting his face by the chin to look at her, and then kissing him on the lips, following with a sincere hug. He's shocked again, but quickly relaxes as he rhetorically asks her where Toothless went. She still likes to tease Hiccup however, as she did with him when she noticed Toothless had entered the Great Hall, before she giddily turned him around so he could see Toothless was back.

Dawn of the Dragon Racers
When Snotlout wins, Astrid tells Hiccup "One out of two ain't bad, and for what it's worth I always knew red was your color". Hiccup responds "Aw, Astrid, thank you," after which Astrid jokes, "I was talking to Toothless." In the flashback, when Hiccup was trying to get the other riders not to have a dragon race, Astrid was the one he asked to back him up. She did at first, but when he saw the other riders racing, including Astrid, he yelled to her, "Really Astrid?! Where's the love for the acting chief?". When Snotlout crashed into Astrid and she fell off of her dragon, Hiccup was worried and upset about her breaking her arm. To prevent her from injuring herself more, he refused to allow her to race after that.

Dragons: Riders of Berk
In the Riders of Berk series they appear to have a budding relationship, but they are quite shy and awkward about it. Their romantic attachment is more suggested in their dynamic and interaction then outright stated. Whilst Astrid maintains more of her initial stern, authoritative demeanor with the other Vikings, she opens up more when alone with Hiccup, and apparently feels safe showing a considerably softer, more whimsical side of her personality to him. The two are incredibly close, with Astrid acting as Hiccup's confidant when he needs advice on personal problems, and often pair off from the others when needing to achieve something especially difficult.

How to Start a Dragon Academy
When Hiccup and Toothless win the best trick contest, Astrid looks on in awe with the others and remarks that "They're still the best!"

When Hiccup is given the responsibility of keeping the dragons out of trouble, he gets overwhelmed whilst running from crisis to crisis, much to Astrid's pity. She pays him a visit later in the evening, announcing her arrival before entering his room, and Hiccup, speaking to Toothless, exclaims, "Astrid... perfect. I don't look too beat up, do I?", which indicates that Hiccup cares what Astrid thinks of him.

After the Academy's sign is hung, the two look on with pride, and Astrid gives him a signature, flirtatious punch in the arm.

Animal House
When Hiccup and Toothless get swept up in an avalanche they, Astrid and Stormfly caused while dragon-boarding, Astrid attempts to save Hiccup, but winds up getting dragged down with him and Toothless along with Stormfly into a huge crevice of snow and ice. In the dark, they come to and call for each other. Astrid tells him that she's freezing and he tells her to come to him. Their dragons use their firepower to open a hole in the ice so they don't freeze, and to let in some light, and in it they suddenly realize that they're holding each other tightly. They both back off awkwardly, assure each other that they're okay, and Astrid teasingly punches his arm again.

Later, Hiccup and Astrid are sitting next to each other while they tell Fishlegs what happened, and when he suggests that had the dragons not been there to shield them they could have used each others body heat to stay warm, they scoot away from each other and blush in awkward denial.

In Dragons We Trust
After dropping their dragons off at Dragon Island, Astrid leans against the ship's mast, and Hiccup quite obviously changes his position to lean against the mast in the same fashion. He then confides in her his suspicions that Mildew framed the dragons for the recent mishaps at home.

Alvin and the Outcasts
Hiccup was hiding so as not to get captured by the Outcasts, until Alvin started painfully interrogating Astrid. It was then that Hiccup showed himself and made a deal with Alvin to leave the people of Berk in peace if he proved he was the Dragon Conqueror.

Later, after he and Toothless reunite, Alvin and his men fire catapult and crossbow rounds at them while in the air, nearly shooting them out of the sky with the latter, before Astrid incinerates the rounds with a blast from Stormfly. After Hiccup asks what kept her, she smiles and teasingly responds with "Why? Did you miss me?"

In the battle that follows, when Astrid falls off her dragon and lands on Alvin's ship, Hiccup is the most concerned for her safety, and he is the first person she looks to for a rescue, which he eventually manages to do after a combined distraction from Stoick's ship and a surprise attack on Alvin by Astrid herself.

How to Pick Your Dragon
Hiccup asks Astrid for advice on how to get his dragon Toothless back from his dad, and she tells him to use the "honey and the hatchet" method. Hiccup says, "Why does your advice always involve weapons?" Astrid just smiles back at Hiccup in response.

Portrait of Hiccup as a Buff Young Man
While Hiccup was protesting to Bucket and Stoick about his portrayal as a muscular teen in the portrait after it was unveiled, Tuffnut asks "Whoa, what happened to Hiccup?", to which Astrid replies "Who cares." in an aroused tone and demeanor.

Later, during the cave-in, Astrid frantically refused to leave Hiccup (who collapsed into a pit), even trying to physically stop Fishlegs from mounting his dragon, until he pointed out that there wouldn't be anybody left to save Hiccup if all of them got trapped. The two were the teens most fervently trying to dig Hiccup out once they were back outside.

Heather Report, Part 1 & Heather Report, Part 2
Though she insists she's not, it's quite clear that Astrid is dealing with feelings of jealously when Hiccup starts neglecting his commitments to her in favor of Heather. She angrily tells Hiccup that his brain is under siege.

In "Heather Report, Part 2", Hiccup wanted to shadow Astrid on her mission to Outcast Island because he wants to be sure she'll be safe.

Later, when Alvin grabs Astrid and runs off with her Hiccup gives chase. Hiccup was also ready to kill Alvin when he threatened Astrid's life.

Before Heather leaves she gives Astrid a good-bye hug, and appears to not even notice that Hiccup was expecting one as well. It appears that Heather had picked up on Astrid's feelings and is keeping her distance out of respect for her new friend.

Astrid gives him another signature punch in the arm after Heather leaves.

Thawfest
Astrid was most proud of and happy for Hiccup when he started scoring victories over Snotlout during the dragon events, and understood his reasons and need to win, at least just once. She was also the most put off by his new demeanor and attitude in response to his victories. When Hiccup revealed a darker, more toxic side of him with regards to the pressure Snotlout was under, she disappointedly tells him that the one thing she always liked about him was that he was a gracious loser (further supporting the theory that Astrid had feelings for Hiccup prior to the first movie) and that she never imagined he'd be such a lousy winner.

Despite this, in the final race, Astrid displays some concern at the fact that Hiccup and Toothless would have to take the longer route of the course and recognizes with a smile his redemption of himself when Hiccup throws the race so Snotlout could keep to his father's high standards. After Stoick's announcement of the victor, she punches him on the arm and tells him she knows what he did. Though he denies any knowledge of what she's alluding to, claiming that Snotlout was 'just the better Viking that day', she praises him saying, "No Hiccup, no one was a better Viking than you today.", before smiling and kissing him for doing the right thing and being himself once again.

When Lightning Strikes
In "When Lightning Strikes", Astrid is the first person that Hiccup seeks out before leaving the island, and when Hiccup tells Astrid that he is leaving with Toothless the first thing that she asks if he will come back. Despite his assurance that he will return when the villagers all realize that the lightning wasn't because of Toothless, Astrid appears emotional and distraught.

When she and Stormfly fly him to the top of the ship's mast, she's genuinely worried about his safety during the electric storm.

What Flies Beneath
Hiccup has to depend on Astrid to give him a ride on Stormfly during much of the episode while Toothless is seeking out the Whispering Death.

Twinsanity
Astrid and Hiccup almost appear to think alike as they try to get Barf and Belch out of danger.

Defiant One
When Snotlout doesn't follow directions and starts heading North instead of South, Hiccup initially doesn't go after him until Astrid, through one word, makes Hiccup change his mind and go after Snotlout. Later when Hookfang returns to Berk, without Snotlout, Hiccup and Toothless, Astrid so concern asking "And where are Hiccup and Toothless?" Later, she shows concern when they find Toothless' tail floating on the water. At the end, she gives Hiccup a smile for rescuing Snotlout even though he had wanted to do so originally.

Breakneck Bog
When the other teens want to flee Trader Johann's Ship and the Smothering Smokebreaths, Astrid is the only one to stay behind to help Hiccup find the treasure said to be from his late mother. She manages to talk the others into staying and helping, too.

Gem of a Different Color
Gobber pairs Hiccup and Astrid together for hand to hand combat, but Hiccup quickly protests, insistent it's not a fair match. It's unclear if he does this in an attempt to be a gentleman, or if he knows Astrid would win with no contest. He manages to dodge her first swing but is quickly pinned to the ground. At Gobber's advisement, he then plays dead, and she gets off of him. As she's helping him back to his feet, she asks if he's ok, and he jokes that his shoulder should pop back into place in no time.

We Are Family, Part 1 & We Are Family, Part 2
When Hiccup is upset that they didn't find any other Night Furies for Toothless, Astrid cheers him up saying that Toothless is pretty happy anyway, because Hiccup is his family.

Live and Let Fly
Astrid and Hiccup are comfortable walking closely side by side on their way back from the arena. When Astrid catches Hiccup flying Toothless against his father's wishes, she chases him down on Stormfly, despite that meaning she was also breaking Stoick's new rule. When she catches him, Hiccup confides in Astrid his feelings on the rule, and they come up with the Secret Dragon Flight Club together. They then explain it rest of the other teens together.

The Night and the Fury
Hiccup gives Astrid the authority to arrange an exercise for the riders and fully supports what she decides to do even though the other riders don't.

Tunnel Vision
When Astrid tells Snotlout that she's sure that's not what Hiccup meant when he started selling water in trade for goods, he says, "Well, that's what makes him Hiccup and me Snotlout." She responds, "That's just the tip of the iceberg."

Fright of Passage
In the beginning when Astrid wants to go after the Flightmare, Hiccup tries to stop her. She says "Come on Hiccup don't tell me you haven't been dreaming about the Flightmare, going after it, learning about it, training it." Then Hiccup says "Well you know Astrid, training dragons isn't the only thing I think about." She then asks him "Are you actually saying that to me with a straight face?" This might suggest that Astrid knows that he thinks about her.

They spend a lot of time alone together on Toothless, chasing the Flightmare. When Astrid gets sprayed by the Flightmare's mist and is paralyzed, Hiccup pushes her to the ground to dodge another attack, and then drags her by the waist to the safety of Toothless, where he lifts her into the saddle. Her fascination with the Flightmare impairs some of her judgement and he has to push or pull her to safety a number of times. At the end of the episode when they were back in the village Hiccup said to the villagers "We learned a lot about the Flightmare and I will explain it all to you but the most important thing we learned was Fearless Finn Hofferson was indeed fearless," Then towards Astrid "just like all the Hoffersons." Then he put his hand on Astrid's shoulder and they smiled at each other.

Appetite for Destruction
When Hiccup prepares to leave Dragon Island to find out what's making the islands to sink, Astrid insists to go with him, saying that it could be something dangerous, showing that she cares for his safety. Later, when Hiccup goes to confront the Screaming Death, Astrid again insists to go with him and when Hiccup tells her to stay for her safety she asks him "So you're leaving me alone?" even though Fishlegs was there too and Fishlegs himself even reminds her of that.

This is also the episode where ironically Astrid tells Fishlegs "No one is kissing me on the lips, EVER!"

A View to a Skrill, Part 1 & A View to a Skrill, Part 2
These episodes continue the trend of Hiccup and Astrid choosing to be close to each other and the pair showing more concern for each other than typical of the others.

Astrid joins Hiccup, and this time Snoutlout, on the mission to find the overdue Bucket and Mulch, after rescuing the missing Vikings from Berserkers it is Astrid and Hiccup alone who speak to the pair. Once the frozen Skrill is returned to Berk, Astrid and Hiccup stand right next to each other with Snoutlout and Fishlegs on either side of the pair. When Hiccup goes to tell his father about the Skrill, Astrid accompanies him and Toothless. While speaking to Silent Sven, Astrid stands next to Hiccup, with Snotlout and Fishlegs on the other side. Although, when they land on the seastack after the Berserker attack, they place Fishlegs between their dragons when they land, this could be due to their secondary positions in the V-formation with Fishlegs in the lead. Then when the two teams reunite Hiccup takes up a position right next to Astrid in the formation.

When the Skrill first prepares to fire on Hiccup and Toothless, it is Astrid that cries out his name and rushes forward to help before the others follow. Then when Hiccup and Toothless dodge and the Skrill fires on the group, it is Astrid’s name that Hiccup cries in alarm, despite the fact that the entire group was fired upon. In contrast, when the Skrill actually hits Snotlout neither Hiccup nor Astrid shows much concern, Astrid actually seems to be deriving pleasure from it.

Astrid also acts as Hiccup’s voice of reason and devil’s advocate for his plans. When Hiccup states that he will follow the Skrill into the clouds by using Toothless’ ability to echolocate Astrid asks if that even works in the clouds. Also, when Hiccup places Astrid in charge of the team attacking the boats and he takes Tuff and Ruff to fight the Skrill, Astrid points out that he needs to be careful because he has more metal than the others.

The Flight Stuff
They're sitting awfully close together on the arena wall watching Snotlout train Gustav, and their hands almost appear to be touching.

Free Scauldy
Astrid gives Snotlout a taste of his own medicine by flirting with him and demonstrates the humor of it for Hiccup. Hiccup awkwardly admits that she's even grossing him out.

Frozen
She runs and hugs Hiccup in front of Gobber when he returned from rescuing Johann, relieved that he's ok after half of their village was paralyzed by the Speed Stingers.

A Tale of Two Dragons
When Astrid knocks on Stoick's and Hiccup's door, Hiccup answers it saying "Ooh what a beautiful night, let's talk outside!" She vents her concerns to him about Snotlout, and he promises to deal with the issue. She finally smiles and tells him "Thank you", and he flirtatiously leans toward her and says, "You're welcome!"

The Eel Effect
Astrid was willing to wait outside in the cold while she was suffering from Eel Pox for Hiccup to come back and was very happy to see him return in "The Eel Effect". These actions suggest that her crush on him is getting harder to hide. He also calls her "young lady" and tells her to get inside.

Cast Out, Part 1 & Cast Out, Part 2
He saved her after Snotlout knocks her and Stormfly out of the sky. He has to hold Astrid back by the waist as she's trying to beat Snotlout up for what he did. Hiccup angrily suspends Snotlout from the academy for almost killing Astrid.

Dragons: Race to the Edge
Beginning with the episode "Blindsided", Hiccup and Astrid are officially a couple. However, even before the events of "Blindsided", it seems as if they both had feelings for each other, and were both aware of their mutual attraction towards one another. Also, when they are alone together, or one of them is in great danger, they aren't afraid to show a little affection.

Dragon Eye of the Beholder, Part 1 & Dragon Eye of the Beholder, Part 2
Hiccup appeared upset that Astrid mentioned that she's done searching for new dragons and is joining the Berk guard, despite saying how happy he was for her. Astrid then advised him to start thinking about what's next for him and Toothless. Hiccup specifically mentions her when talking to Stoick, while not bothering to name the others or tell his father what they are up to.

Hiccup also dives down to save Astrid after she falls into giant eel-infested waters.

Then while Hiccup is exploring the Reaper, the Dragon Riders are captured by Dagur and locked in a cage on the Reaper. When Hiccup meets Dagur again after three years, Astrid is one he cries out for. Dagur also calls Hiccup a "ladies' man" vaguely indicating Astrid, which shows he has noticed his feelings for her. Hiccup simply ignores this.

Imperfect Harmony
After they land on Melody Island, Hiccup and Astrid spend most of their time together and even sleep next to each other. When the Death Song is about to shoot at Hiccup, Astrid pushes him away and the amber immobilizes her.

When Darkness Falls
In "When Darkness Falls" there are several instances which point to the complex relationship that has developed between the two to this point and establishes a theme that carries through the entire series.

When they first land on Dragon's Edge and Hiccup takes charge of having them set up the camp, Snotlout complains about liking "whiney Berk Hiccup" more than "Princess outpost Hiccup" to which Astrid replies, "I know, right?" before giving Hiccup a secret double thumbs up.

Then the next day when everyone is pushing their ideas for the outpost Astrid smiles when Hiccup states that they need one idea as if she fully expects Hiccup to choose her design and then gets upset when Hiccup states that everyone else's ideas are good too.

However, what is perhaps the most telling is the layout that Hiccup chooses for Dragon's Edge. Hiccup placed his hut right next to Astrid's hut and they are closer together than any of the other huts.

Gone Gustav Gone
When Hiccup asks Astrid to watch Gustav, she sarcastically responds with "Great, so now I'm a babysitter!", to which he laughs very nervously. However, the fact that Hiccup asked Astrid and not anyone else shows just how much he trusts her.

Reign of Fireworms
When Astrid is "locked up" Hiccup asks her, "So, what are you in for?", to which she replies, "Not funny!", and when Hiccup is "locked up," she asks him the same thing. This indicates that they like to make fun of and tease one another.

Have Dragon Will Travel, Part 1 & Have Dragon Will Travel, Part 2
In "Have Dragon Will Travel, Part 2", Heather asks Astrid if she and Hiccup are a couple. First, Astrid panics and throws her axe into the top of a tree. Then she adamantly states the two are just friends, though she appears a little nervous on the matter, and it is clear that Heather doesn't buy her denials.

Also, when Heather teases that Hiccup is kind of cute, Astrid blushes, smiles and says, "I guess. If you like that unassuming, heroic, dragon rider type." At the end, Hiccup feels sorry for Astrid losing a friend, knowing the two got really close. Astrid then puts her arm around Hiccup and states, "But I still have you."

The Next Big Sting
Astrid is visually concerned, biting at her fingers when Hiccup jumps off the cliff with his new flight suit, Dragon-fly 1. She looks to Toothless for some reassurance that he'll be ok. Later, when Hiccup says the Stingers' webbed feet have given him some ideas for "something he's been working on", Astrid tells him that if he says "Dragon-fly 2", she's going to lock him up, indicating she's sick and tired of him needlessly putting himself in danger.

Team Astrid
After an attack on Berk, Astrid finds out that her Astrid's parents house got destroyed during the attack. Fortunately, her parents were out when the attack was taking place.

Astrid tells Hiccup that she will be staying in the arena and Hiccup said that he's staying there too, due to his dad's loud snoring, but he was really trying to support her. When she decided to stay on Berk to train new riders, Hiccup stayed too, saying that it was to patrol the island, but he really stayed on Berk to be with Astrid.

Night of the Hunters, Part 1 & Part 2
At the beginning of the episode, Hiccup is worried that Astrid has been gone all day without telling anyone where she's gone.

Feeling that something's wrong, he decides to lead the others on a search party to find her. When Snotlout mentions Astrid likes to fly South, when Hiccup tells them each a direction, while he goes South, Hiccup refuses to let Snotlout go South. Hiccup sees her as she begins to sink into the ocean and immediately dives in to save her.

As Hiccup pulls her out of the water, he holds her on his lap, and shouts her name, fearing the worst. After a few seconds, she weakly regains consciousness and asks, "What took you so long?". Hiccup then holds her in a tight hug thanking the gods she's alright, his panic still evident. She then appears to fall asleep with her head on his shoulder.

For some reason, when they return to the Edge, he brings her to his hut instead of her own and lays her in his bed to let her sleep the experience off.

Snotlout Gets the Axe
Hiccup shows no worries at the various jokes about Astrid and Snotlout someday marrying because he has full confidence that it'll never happen.

The Zippleback Experience
At seeing Toothless alone, looking out over the sea, Astrid knows Hiccup is in trouble, and she leads the other Riders on a search for him.

Snow Way Out
During the course the episode, Astrid tells Heather that she is worried about not telling Hiccup about Heather's spying on the Hunters, explaining to her that she knew Hiccup trusted her and that she has never lied to him before. While Heather reassures her that this is a necessary sacrifice, Astrid still looks doubtful.

A little after this event, Hiccup tells Astrid that he relies on her. Astrid looks taken aback by that, remembering her talk with Heather. At the end, Hiccup is upset when Astrid tells him that Heather was helping them since he is surprised that Astrid was keeping a secret from him that could help them. He also seems to feel personally betrayed, as he has trusted Astrid with secrets in the past that he had never shared with anyone else. Although he acts coldly towards her for a time, they seem to reconcile by the end of the episode.

Edge of Disaster, Part 1 & 2
When Hiccup prepares to leave, Astrid implores him to not leave her alone, but in the end, she accepts to stay on the Edge. Later in the episode, she says "Hiccup, where are you when I need you?". When Hiccup finally arrives, she is so happy that she even punches Dagur when he insults Hiccup.

Maces and Talons, Part 1 & 2
When Astrid is worried about Heather's safety while working with the Hunters, Hiccup reassures her that she will be fine, and they look longingly into each other's eyes until Snotlout and Tuffnut destroy the moment.

Enemy of My Enemy
At the beginning, Astrid confronts Hiccup because he wants to go on a patrol alone, saying that it is too dangerous and trying to convince him that he won't find Viggo. She is worried that Hiccup will wear himself into the ground looking for Viggo.

After Astrid realizes that she can't change his mind, she insists that he allow her and Stormfly to accompany him. However, he leaves without her when she goes to get Stormfly.

Later at the island when Toothless is incapacitated and Hunters are looking for him, Hiccup mentally beats himself up for not listening to Astrid.

Buffalord Soldier
In the episode "Buffalord Soldier", Astrid becomes deadly ill with a disease called "The Scourge of Odin", and even before Hiccup knows she is sick, he is very concerned. His anxiety heightens when Stormfly comes to him in a panic and leads him to Astrid, whose symptoms are much worse. Hiccup paces around the floor, as Fishlegs searches for a cure, and catches Astrid when she collapses, concern etched in his face.

When Astrid falls off of Stormfly after she is brought to the Buffalord, Hiccup catches her, clearly still worried. He comforts her as she whimpers in pain, telling her that they will beat the illness and that she must keep fighting, confessing that he couldn't imagine a world without her in it. He begins to panic when the clear Buffalord saliva does not cure her. Hiccup holds Astrid's hand and begs her to stay alive a little longer, for him.

When Viggo arrives to take the dragon, he reveals that it was his boat where Astrid caught the Scourge, which antagonizes Hiccup more than Viggo usually does. Viggo threatens to kill the dragon if the Riders will not let his Hunters capture it, but Hiccup begs him to let him collect the green saliva and tells Viggo that "that's a loss I'm NOT willing to take" before they take it away. He's basically telling Viggo that he refuses to lose Astrid. Afterward, he willingly allows Viggo and his men to take the dragon away, knowing that Astrid's worth it and that the Buffalord would be impossible to move off the island anyway.

Finally getting the green solution, Hiccup urges Astrid to drink and then helps her up as color comes back to her face. Astrid stumbles at first and nearly falls, but Hiccup catches her and steadies her on her feet.

After giving the Vikings on Viggo's ship a Viking funeral, Astrid thanks Hiccup for saving her life and adds that she owed him, after which he tells her that it wasn't a big deal and he was sure she would have done the same for him. Astrid too confesses she couldn't imagine a world without Hiccup in it, as the both of them smile at each other.

A Grim Retreat
Astrid is the one who convinced Hiccup to go to an island to relax. At the campfire, they stay together. When Toothless and Hiccup go the water Astrid says, "Come on, come on," showing she cares for his safety.

To Heather or Not to Heather
When Astrid and Heather are talking, Heather mentions Hiccup, and Astrid smiles and looks to the ground, asking, "What about Hiccup?". Heather tells Astrid to express her feelings to Hiccup and declares that the two of them are perfect.

Stryke Out
When Snotlout accidentally gets Hiccup and Toothless captured and taken to the dragon fights, Astrid is very worried, and when she finds him she runs to him and hugs him.

While they are flying out, Astrid says that she is glad to have Hiccup back and that she had been worried. Snotlout says he wasn't worried, though Fishlegs says that Astrid would've killed him if they hadn't found Hiccup.

Tone Death
When Snotlout states that Hiccup can "have" Astrid, Hiccup laughs and says, "Thanks, I appreciate that".

Family on the Edge
Astrid threatens to kill Dagur, thinking he did something with Hiccup. When Hiccup appears, she pokes him in the chest in an accusatory manner, and he pushes her finger away with his fingertip, laughing nervously as they both look at their fingers. When they are finished talking about Dagur, they look at each other and smile a little bit.

Last Auction Heroes
When the riders are captured, Astrid puts her hand on Hiccup's shoulder and he looks at her and puts his hand on hers. Later in the episode, when Hiccup is drowning, Astrid and Stormfly dive in and catch him.

Defenders of the Wing, Part 1
When they're walking toward the Defender's village and spot the assassins in the trees above, Astrid catches a blow dart in mid-air before it hits Hiccup. Later as Hiccup tries to train the Speed Stingers, Astrid frantically calls for him and attempts to jump into the pit to help him, but she is stopped by Mala blocking her path with her sword and Throk holding her back.

Midnight Scrum
At the beginning of the episode, Astrid helps Toothless save Hiccup from the bounty hunters. When they are alone in the Great Hall, she places her hand on his and tells him to inform Stoick about the bounty. After Astrid and the other riders find Hiccup, she immediately rushes over to him and helps him stand without his metal leg.

Dire Straits
After dragging Hiccup out of the diving bell onto the deck, Astrid frantically calls his name, worried that he isn't breathing. When he finally wakes up she is relieved to see that he's okay, kneels beside him, and puts her hand on his shoulder. It shows how much she cares for Hiccup and wants him to be safe.

Gold Rush
Astrid panics when she sees Toothless without Hiccup, but is visibly relieved when Hiccup escapes Viggo's ship.

Out of the Frying Pan
Astrid starts to panic when too much time has passed after Hiccup, Fishlegs, and Mala enter the cavern. She agrees to join Throk in fetching them before the lava rises too high, putting themselves in danger. Just before Astrid passes out from the heat in the lava pit, she mutters Hiccup's name, and when Hiccup, Fishlegs and Mala spot Astrid and Throk, Hiccup lifts Astrid onto his lap to take her to safety.

Twintuition
As they are flying Stormfly gets hit by a boulder and Astrid falls off. Hiccup goes to save her, and as he grabs her arm he says "I got ya". When they land he steps forward a little to check if she's ok.

Blindsided
After Astrid is blinded and knocked over by a strike of lightning, Hiccup expresses his concern over her condition, speaking with her alone and trying to reassure her that everything will be okay, in spite of feeling unsure himself.

Later, while riding on Toothless, Hiccup grabs Astrid's waist to prevent her from falling off, telling her to hold on tighter. She apologizes, but he tells her it's fine, admitting he's glad that she's there with him. She then hugs him, which makes him smile.

When they land, Astrid begins walking off on her own to find Stormfly, and when she trips over a rock, Hiccup leaps for her, wrapping an arm around her waist and shielding her head from hitting the ground as they fall, leaving them in an awkward situation. Hiccup freezes for a moment and makes no move to stand up until Astrid hesitantly suggests that they get moving again. When the Triple Stryke first appears, Hiccup pulls Astrid out of the way and shortly after has Toothless grab her and move her to a safer position. Astrid protests hiding on the sidelines when Hiccup needs her to help fight the wild dragon, but both Hiccup and Stormfly force her to stay hidden, worried that her blindness will put her at a higher risk.

After Hiccup fends off the Triple Stryke, Astrid dejectedly expresses her feelings of frustration, helplessness, and fear that her condition might be permanent. Hiccup takes her hand and assures her that she will never be helpless, even if she remains blind, and that he will always stand by her, no matter what. He pauses for a moment and leans in to kiss her, but they are interrupted by the return of the Triple Stryke, who tries to attack them. Hiccup manages to grab Astrid and dive out of the way of the attack just in time, turning in midair so that he lands beneath her, shielding her from impact. When Astrid approaches the Triple Stryke on her own to train it, Hiccup tries to stop her, but she brushes him off and proceeds to train it in spite of her blindness, proving Hiccup's earlier point that she is not helpless in her current state.

Later, at Astrid's hut, Gothi manages to heal Astrid's sight, much to Hiccup's evident relief. Overcome with happiness, Astrid suddenly embraces him, catching him off guard at first, and he hugs her back.

Afterwards, the two sit outside the dragon stables and watch the sunset together. Hiccup asks Astrid if she feels well, and she tells him to stop worrying so much about her. He admits that he never stops worrying about her, and she agrees that she is the same way about him. Encouraged by her answer, Hiccup slides closer to Astrid, who playfully nudges his side. After a moment, Astrid hesitantly asks if he had been about to kiss her earlier, which he sheepishly admits to. When she asks him why he didn't go through with it, he answers that the moment wasn't perfect, and that, although he has thought about it for a while, he has never found the right moment to kiss her. Astrid smiles and glances at the sunset before telling him that this moment seems perfect to her. Hiccup agrees, and the two finally share a kiss, initiating their now romantic relationship. Afterwards, the two lean affectionately against each other and watch the rest of the sunset together.

Shell Shocked, Part 1
Astrid congratulates Hiccup for creating the perfect plan to capture and defeat Viggo. Hiccup is still nervous and unsure, but Astrid assures him that the plan will work. They attempt to share a kiss but are interrupted by Fishlegs. Fishlegs believes they're thinking of ways to hide the Dragon Eye once regaining it, completely oblivious of their romance.

Hiccup and Astrid are relieved and decide for the time being to keep their newly formed romantic relationship a secret from the rest of the Dragon Riders. Hiccup puts his hand out for a handshake but Astrid grabs it and pulls Hiccup to her and the two share a kiss. After the kiss as Astrid gets ready to leave, she says to Hiccup, "Did you really seriously think I would leave here with just a handshake?" Right after Astrid leaves, Hiccup tells Toothless that Astrid is really something else.

Eventually, the rest of the Dragon Riders begin to notice a change in Astrid and Hiccup, but are oblivious of their newly developed romantic relationship and instead theorize different reasons for their behavior.

While Ruffnut and Tuffnut believe that Hiccup is going to die and Snotlout believes he has developed a gambling problem, only Heather becomes aware of their romance and allows the couple to have time alone together.

Shell Shocked, Part 2
Viggo is aware of Hiccup and Astrid's relationship, and taunts him with it, telling him how odd it is that he is in love with a girl who is his partner in battle, which winds Hiccup up, but he forces himself to concentrate on the task at hand, to stop Ryker.

After defeating Ryker, Hiccup goes to check on Fishlegs. After Fishlegs leaves, Viggo lands on Stormfly holding Astrid captive with her own axe to her throat and states that he will release her in return for the Dragon Eye, asking Hiccup if he is going to sacrifice his future for it. Hiccup throws the Dragon Eye into the volcano, which makes Viggo let go of Astrid and run to it, thus showing that Hiccup will do whatever it takes to protect Astrid. At the end of the episode, just prior to the explosion of the volcano on the Edge, Hiccup, and Astrid end up kissing after promising to keep their relationship out of the war with Viggo, and their kiss is seen by the other Riders, erasing Ruff and Tuff's suspicions about an 'illness'. Snotlout, on the other hand, seems to be convinced of a gambling problem.

Living on the Edge
After discovering an injured Garff, Astrid tells Hiccup to return to the Edge while she stays with the dragon until what seems to be his inevitable passing. Hiccup is clearly worried about leaving her alone on the island, but she assures him that she will be fine and that she has Stormfly to protect her. Hiccup relents and kisses her forehead in farewell.

Sandbusted
At the beginning of the episode, Hiccup is caught by Snotlout holding his betrothal gift for Astrid and has to explain to him what it is. He says it means he and Astrid will be together forever. Astrid, meanwhile, is struggling to find a gift for Hiccup and when the gang goes to the Northern Markets after getting a T-mail from Trader Johann, Astrid is still unable to find anything to give him. At the end of the episode, Hiccup presents his betrothal gift to Astrid. As he gives it to her he says "This was my Father's betrothal gift to my Mother, and he gave it to me to give to you. Astrid you're a part of our family, you always have been, and I hope you always will be." Astrid sheds a sigh which Hiccup misinterprets as dislike for the gift and says "Well if you don't like it..." Then Astrid shows a loving smile and says "Hiccup I-it's it's beautiful, it's perfect," She sighs in disappointment and says "It's just I, I didn't get you a gift I don't know what to get." Then Hiccup interrupts her, smiles and says "But you did. Astrid, you got me the greatest gift in the world. You. You just being here with me is the only gift I need." Hiccup pulls Astrid into loving hug. The two of them have been officially betrothed for six moon cycles.

A Matter of Perspective
Astrid first walks up to Hiccup in his hut where he is trying to hide the Dragon Eye 2 and talks about his "secret project" teasingly. Later in the episodes, she says with humor about how there are so many secrets.

Towards the end of the episode Hiccup and Astrid are walking to their huts and Astrid asks how Hiccup figured to get past a new dragon they encountered. Hiccup tells her that it's all about perspective and that it's pretty cool to think about and grabs her hand. Astrid then says she's going to get some sleep, and they share kiss.

Dawn of Destruction
At the beginning of the episode, Hiccup and Astrid are doing combat training together. Hiccup and Astrid take a "vacation" to an island to find a Sassafras plant. At the same time, they say "Do you think we should have stayed at the edge?". They laugh, then lean on each other while looking into the distance. "I just want to make sure." Hiccup says, "But at the same time, spending time with you is important." Astrid hugs Hiccup. "What was that for?" Hiccup asks. "Just for being you. I love how sensitive you are." Astrid replies. "Don't tell that to Stoick." Hiccup responds. "Oh, I think he knows. Everyone knows. It's what makes you such a great friend, a great leader, and, um, a great boyfriend." Astrid replies. Hiccup then asks her if she wants to go on a moonlit flight with him, to which she answers, "Thought you'd never ask!" before playfully flipping him over onto the ground. After that Hiccup and Astrid take a romantic, moonlit flight.

The Wings of War, Part 1
When Hiccup is concerned about defeating the Dragon Flyers, Astrid optimistically says that he'll come up with something. When asked how she knows that, she states that it is "Because Hiccup Haddock is the wisest, most talented and brave Dragon Trainer on Earth. And he always comes up with it."

At the end of the episode, Astrid finds Hiccup alone on a sea stack, where she asks him about his problems. After a short conversation, Hiccup accuses Astrid of sounding just like his father. He then prepares to leave to find another solution. When Astrid asks him about what would happen if he can't, Hiccup doesn't answer and takes off on Toothless.

The Wings of War, Part 2
Hiccup is relieved to see Astrid again at the end of the battle and tells her that she had him worried.

Snuffnut
When Tuffnut speaks with Hiccup and Astrid about Ruffnut and Throk, Astrid is seen helping Hiccup construct his Dragon Eye. Astrid then moves behind Hiccup and puts her hands on his shoulders as she gently asks Tuffnut if he wouldn't want to meet a beautiful Viking girl and start a family himself, trying to help him understand Ruffnut's position with Throk. Hiccup glances back at her knowingly as she is speaking, as if he senses she is referring to their own happiness as a couple. They spend much of the episode standing and interacting with each other exclusively.

Searching for Oswald... and Chicken
Right before leaving for Vanaheim, Tuffnut becomes desperate to find his Chicken. Astrid then offers to stay behind and look after the twins and Hiccup thanks her.

Sins of the Past
Near the end of the episode, Hiccup asks Astrid where Dagur is. She points to Dagur, who is comforting Heather. "What was in the letter?" Astrid asks. Hiccup answers with "closure" and wraps his arm around her waist. Astrid puts her arm around his waist and rests her head against his.

No Bark, All Bite
While flying to Berk Astrid talks to Hiccup encouraging him to go tell his dad. Hiccup agrees and says it can't be too bad. When Stoick and Hiccup start Arguing about the Trade Ships that came Astrid tells Hiccup Stoick has a point. Hiccup agrees again and goes off to find Stoick. After the attack, Hiccup asked everyone if they were ok and Astrid replied with a smile and a nod.

Mi Amore Wing
At the beginning of the episode it's brought up that Mala and Dagur are getting married and the way they act together makes Astrid question her relationship with Hiccup. Astrid later puts on the Betrothal Necklace Hiccup gave her hoping he would notice it. When Hiccup comes to her hut he does not notice the necklace. Later she hints Hiccup on how she is wearing the Necklace but instead, Hiccup notices the Dragon Eye Lens on the Armor Wing which makes Astrid angry. When Hiccup notices how Astrid is acting he walks over to her and asks what she is trying to tell him in which Astrid gets angry as she tells Hiccup that he has been ignoring her and the fact she is wearing her Betrothal Necklace and throws it back at Hiccup. However, later on, she and Hiccup makeup and work together to fight Krogan and his Flyers. At the end of the episode, Hiccup apologizes saying "I love you, Astrid Hofferson with all I have, and I always will." Astrid blushes and then Hiccup pulls Astrid in for a passionate kiss taking her by surprise. As they look at each other Fishlegs, Mala, and Dagur walk away to give the two some privacy, and Hiccup and Astrid lean on each other and look out at the setting sun.

Ruff Transition
On Wingmaiden Island during the grand transition, Hiccup, and Astrid are standing next to each other. When the baby dragons come out they hold each other's hands and gaze affectionately at each other. Later in the episode, Astrid tells Hiccup to help Ruffnut with Wingnut.

Triple Cross
Hiccup and Astrid are spending some alone time, having a picnic with no distractions, and no interruptions, till the twins come crashing down. As Hiccup was about to leave, Astrid was worried that the message didn't sound like Stoick and wanted to go with him but he assured her that he would be careful.

Darkest Night
After Stoick is injured Astrid asks in concern how he is twice and is the one to tell Hiccup he has been voted as acting chief. She leaves him alone when he refuses at his request. As Hiccup sits alone (with Toothless) at a table in the Great Hall worrying about his dad, Astrid comes up and tries to help reassure him by saying it was not his fault. When Tuffnut says "actually it is his fault" Astrid stands up and mouths angrily "WHAT?" at Tuff. She doesn't share a story on what Berk would be like with the others and seems concerned after Hiccup storms off. Astrid then meets Hiccup as he's with Toothless staring at the sea once again and refuses to leave him alone. She tells a story about how Toothless and Hiccup was meant to be best friends and how even if he missed when he was 15, they still would have come together and his father would still be in that position. Hiccup thanks her and regains his confidence quite a lot due to her speech.

Guardians of Vanaheim
When Hiccup decides to lead the riders to Vanaheim, Astrid asks Hiccup if he was sure he wanted to do the mission. Hiccup reassures Astrid and says that he can't do more than pray to the gods his dad gets better. Later, when the riders find the Sentinels, Astrid walks over to Hiccup and puts her hand on his shoulder. Later, while in the wrecked Dragon Hunter Ship, Astrid encourages Hiccup, in which Hiccup responds, "Where do you come up with this stuff?" Astrid replies with, "Hm, does it really matter?" and they look at each other affectionately. While Snotlout stays behind, Astrid asks where is Snotlout, and Hiccup said he stayed behind to take care of Hookfang, who got struck by lightning. Astrid then says "Ugh, looks like it's you and me then." Hiccup then replies "Always. Was that corny or-" Astrid then laughs and agrees, but says it was nice.

King of Dragons, Part 1
Astrid comes into Hiccup's hut and tries to comfort him as he is looking frantically for something. He announces he will defy Berk's orders to be chief and instead look for the King of Dragons, and he then says to Astrid that she can either come or "pray he comes back alive". Astrid says all along she was going to follow him. He then touches her cheek and thanks her for everything then takes her hand showing the start of how their relationship is in How to Train Your Dragon 2.

King of Dragons, Part 2
Near the beginning of the episode, Astrid is about to leave to go fight the dragon flyers. When Hiccup grabs Astrid's wrist, Astrid then talks to Hiccup and giving him support and telling him to find the king of dragons or the war would go on forever. Astrid says she's proud of him and kisses him on the cheek. Hiccup pulls Astrid back as she starts walking away and kisses her on the lips, Astrid then smiles, and brushes her hair out of her face and puts her hand on his heart. Near the end, Astrid and Hiccup are shown kissing at Dagur and Mala's wedding.

How to Train Your Dragon 2
Astrid and Hiccup are not only an official couple by the sequel, but are betrothed. This is shown during the Dragon Race at the beginning when Stoick proudly yells "That's my future daughter in law!" after Astrid grabbed the black sheep from the twins.

After the race, Astrid and Stormfly track Hiccup and Toothless down at Itchy Armpit, where he greets her with "Afternoon, m'lady!" Astrid then sits on the ground beside Hiccup, and gestures for his pencil so she can add something to his map. Hiccup hands it over without a second thought. They sit so close together, they always appear to be touching in some way, or even leaning on each other. Hiccup vents to Astrid how Stoick is pressuring him to take on the role of Chief, and she teasingly mocks him, to which his reaction is both confusion and amusement. They both laugh, and Astrid even punches Hiccup in the side similar to how she did when they were younger. When they settle down, Astrid states how proud she is of Hiccup, while he confides that being Chief just isn't him, and he's still searching for who he really is. At that, Astrid leans against Hiccup's side and casually braids his hair, telling him that what he's searching for isn't "out there", but within himself. Astrid puts her hand on Hiccup's chest and he gives her a genuine smile, before she leans in and kisses him on the cheek. The scene ends with Hiccup cupping Astrid's face in his hand to draw her attention to smoke he sees in the distance.

When flying their dragons toward the smoke, they share a concerned glance, and Hiccup tells Astrid to "stay close" for safety. When Eret shoots Stormfly out of the sky, Hiccup has Toothless dive to catch Astrid. Once landed, Hiccup quickly pulls out his flaming sword to defend himself and Astrid from the Dragon Trappers. After some unproductive conversation with Eret, Hiccup cuts Stormfly loose and allows her and Astrid to get ahead of him and Toothless as they make their escape.

They return to Berk and Hiccup tries to tell his father what they learned from Eret, which eventually leads to Stoick preparing to put the village on lockdown. Hiccup chases Stoick down the stairs to the caves beneath the village, and Astrid follows close behind. When Stoick refuses to listen to Hiccup's reasoning, Hiccup decides to do something on his own. Astrid tries to stop Hiccup, but he tells her he has to do something, and gives her a quick peck on the cheek, before mounting Toothless and escaping the stronghold before all the doors are shut. At the last possible moment, Astrid decides to join Hiccup and they head back toward Eret's ship.

At arriving, Astrid appears to be shocked at Hiccup's plan but fully trusts him as he gestures for her to put her axe down, throws a net over her, and leads her gently to the ship's storage compartment. Astrid is still confused but doesn't protest when Hiccup shuts the two of them in it. After Hiccup talks to Eret for a bit, Astrid adds that Hiccup can be very persuasive.

When Stoick and the Riders "rescue" Hiccup, he tries to talk some sense into Stoick so he'll let him go try to keep the peace. Astrid locks eyes with Hiccup and gives him an encouraging smile and nod, showing she agrees. Hiccup flies off in frustration, and Astrid tries to follow again but this time is stopped by Stoick, insisting she escorts the other Riders back to Berk instead.

Sometime later, Astrid and the Riders are resting on an iceberg, and Astrid becomes worried as neither Hiccup or Stoick had returned yet. Astrid decides to lead the other Riders on a mission to find Hiccup despite what Stoick ordered her to do.

The couple doesn't see each other again until the battle with Drago and his army, where Astrid asks where Hiccup's been. Hiccup answers, saying he was catching up with his mother, to which Astrid asks in shock if the character leading the giant dragon into battle is really his mother. Hiccup's response is "Now you know where I get my dramatic flair!"

When Stoick is killed, Astrid is in shock and even appears emotional as she jumps off Stormfly and runs to Hiccup's side. Astrid cuddles up beside Hiccup, puts an arm around his back, and leans her head against his, in an effort to bring him some comfort. At learning Drago is about to fly Toothless away, Astrid attempts to hold Hiccup back as he emotionally jumps up and tries to run toward his dragon. Later at the funeral, Astrid is on the far right along with Valka, which traditionally is a position of honor during official practices. Astrid looks on with great pride when Hiccup rises to his new chieftain role and states how they're going to go back, reclaim their dragons, and save their home.

When flying on the baby Scuttleclaws, Astrid asks Hiccup if Drago's Bewilderbeast will take control of them too, to which he answers, no, since they're just babies. Back at Berk, after Hiccup gets Toothless back, Astrid excitedly calls out, "Take 'em down, Babe!", as Hiccup tries to fight Drago and his dragon. When the Bewilderbeast blasts Hiccup and Toothless with ice, Astrid looks terrified, similar to how she did in the first movie when she thought he might be dead. But her expression turns to one of awe and relief when Toothless breaks them out.

After Drago's defeat, Astrid approaches Hiccup and tells him "See? I told you it was in here," as she punches him in the side again, letting out his flight suit's dorsal fin. They and everyone else laugh, and Hiccup pulls Astrid close and gives her a long passionate kiss on the lips. When Gothi officially appoints Hiccup as the new Chief, Astrid can be seen beaming with pride behind him.

The movie ends with another Dragon Race, during which Hiccup steals the extra-pointer black sheep from Astrid, only to toss it into her basket instead of his own, making her the winner again. The two are the only Riders perched on the race platform at the very end, with the others on the level below.

Burning Midnight
After being trapped in a cave surrounded by rogue dragons, the gang share stories and Astrid retells the brief events of her conversation with Stoick before following Hiccup to Itchy Armpit. Valka, upon hearing the story, expresses her gratitude to Astrid for taking care of Hiccup and being the daughter she and Stoick always wanted.

The Serpent's Heir
Before heading off to Nepenthe, Hiccup decided to make Astrid the acting-Chief. Astrid, however, ends up appointing Gobber as her acting-Chief so she can join Hiccup on his visit to keep him out of trouble.

After returning back to Berk, Hiccup appoints Astrid to the General of Berk so they can lead Berk as a pair by working together as Chief and General.

Deleted Scenes
How to Train Your Dragon: "An Axe to Grind"

An Axe to Grind was deleted because of the length, not the content. It's therefore considered canon by director Dean DeBlois.

This deleted scene gives insight into Hiccup and Astrid's relationship prior to dragon training. It also shows Gobber encouraging and teasing Hiccup about his crush on Astrid.

Near the end of Axe to Grind, Astrid thanks Hiccup for sharpening her axe and then pulls her hair away from both of her eyes with a smile. She does the exact same thing before kissing him in the cove and after almost kissing him in "Animal House". This suggests that Hiccup's crush wasn't completely unrequited.

"She [Astrid] is pretty much most of the time is looking at with one and a half eyes. We wanted to make sure that she would flick and she wouldn’t really notice she’d be doing it… In the film where she kisses [Hiccup] what she does is pulling her hair away from both eyes. It helps to give the idea that she’s opening up a little bit.."

- The Making Of How to Train Your Dragon - Animator's Corner

Gift of the Night Fury: "Missing Toe"

Everyone else has black eyes suggesting Astrid had punched them in the face, while Hiccup still gets his signature punch in the arm.

How to Train Your Dragon 2: "Stoick's Funeral"

Astrid attempts to comfort Hiccup before the funeral speech.

Games
There are several references to Hiccup and Astrid's relationship in the games.

School of Dragons
As a science education game aimed at younger children, School of Dragons does not discuss the romantic relationship between Astrid and Hiccup. However, it is hinted at in various player Quests and other activities. Astrid's and Hiccup's Relationship is alluded to in the Farm Job asking the player to grow and sell sunflowers.

"Hiccup wants a bouquet of flowers for a certain Hofferson. Oh ho ho!"

- Trader Johann

While recieving a quest during the "Wrath of Stormheart" Expansion, Snotlout hints a little about Astrid's and Hiccup's romatic Relationship.

"I received a Terror Mail form the Lovebirds. What? Hiccup and Astrid are fine. Eww, no..."

- Snotlout

Astrid playfully teases Hiccup during the Quest "That Time of Year, Part II". Hiccup has just played the Snoggletog Dragon Tactics mini-game with the player. Astrid built it to bring everyone together - through training - for Snoggletog.

In a Farm Job, Astrid and Hiccup go on a picnic and require cabbages, tomatoes, and chicken eggs.

Dragons: Rise of Berk
In one of the dialogues in Dragons: Rise of Berk, Hiccup and Astrid have an argument which ends up being resolved with them sharing a picnic, showing how they can't hold a grudge against each other.

Later, in a Snoggletog Gauntlet event, Johann gives Hiccup a map to Hamish I's lost treasure. Astrid wants just her and Hiccup to go on the Quest for the treasure. It turns out that the map was fake and planted by Krogan to get at Hiccup.

"I think it's a great idea, babe. Let's find it. Just you and I, okay? What's the first clue?"

- Astrid to Hiccup

Behind the Scenes

 * In 2013, former president Barack Obama visited DreamWorks Animation studio in Glendale, California where animators showed him how they use motion capture technology for the Itchy Armpit scene from How to Train Your Dragon 2. This was the first official glimpse of Hiccup and Astrid's relationship in the sequel.
 * During the promo of How to Train Your Dragon 2, Jay Baruchel and America Ferrera joked about what Hiccup and Astrid's power couple name would be.
 * During a press tour in 2014 former DreamWorks Animation CEO Jeffrey Katzenberg spoke a bit about Hiccup and Astrid's relationship and called Astrid "Hiccup's equal in every sense".
 * At one point in an interview with Everything Geek Podcast, back in February nine days before Season 4 of RTTE was released, while Douglas Sloan and Art Brown were talking about Hiccstrid, Douglas Sloan said this about Hiccup and Astrid's relationship. "It's not just gonna happen and that's it, we are going to deal with their [Hiccup and Astrid's] relationship in many ways going forward and until the end of the series. It's something that will become a big part of the series."
 * In a Valentine's Day livestream with some of the crew members from Race to the Edge it was revealed that season 6, by far, has the most 'Hiccstrid' moments of any single season.
 * According to feature film animator Kevan Shorey, Hiccup and Astrid's relationship will be a part of How to Train Your Dragon: The Hidden World. This statement is supported by film critic Jacob Tiranno's experience of a 3 minute sizzle reel of the third movie, which was unveiled by DreamWorks Feature Animation Group president, Chris DeFaria, at Cinemacon 2018.

Trivia

 * Hiccup and Astrid's relationship is usually shortened to "Hiccstrid" when referred to in a romantic context. It is mentioned on-screen for the first time in Dragons: Race to the Edge, Season 4 episode "Shell Shocked, Part 1" by Snotlout. And it is mentioned in  Dragons: Race to the Edge, Season 5 episode "Dawn of Destruction" by Snotlout again.
 * The author of the How to Train Your Dragon books, Cressida Cowell, has tweeted that she loves Hiccstrid too.
 * She also wrote a thanks to Jay Baruchel and America Ferrera for voicing Hiccup and Astrid at the end of her last book, "How to Fight a Dragon's Fury".
 * In the song, "Fly Dragons Fly," which aired on Cartoon Network, a part in the lyrics said, "Astrid and Hiccup, each other they like. Wonder if they marry? They might."
 * Astrid and Hiccup have kissed on the lips 11 times on-screen.
 * At the end of "Mi Amore Wing", Hiccup kissed Astrid for the first time, instead of the other way around.
 * They have also shared 4 cheek kisses, with Astrid having kissed Hiccup on the cheek thrice, and Hiccup having kissed Astrid on the cheek once.
 * Hiccup has kissed Astrid on the forehead once as well.
 * They are the only ones throughout the franchise who kiss besides Stoick and Valka.
 * "Mi Amore Wing" is the first episode we hear Hiccup say he loves Astrid.
 * "Mi Amore Wing" is also the only episode where we hear Hiccup say he loves Astrid using her full name.  "I love you Astrid Hofferson."
 * Hiccup liked Astrid before Astrid liked him.
 * Astrid always screams "Hiccup!" when something happens to him and Hiccup always screams "Astrid!" when she is in danger.
 * Snotlout tells Hiccup that he can "have" Astrid because he likes Heather. Hiccup laughs and thanks him, acting like he already KNOWS who Astrid has chosen.
 * In the episode "Dawn of Destruction" Astrid uses the word boyfriend for the first time in the franchise, when telling Hiccup that she loves how sensitive he is and that it makes him a great friend, a great leader and a great boyfriend.
 * At the end of HTTYD2 just as Astrid and Stormfly are about to catch the black sheep Hiccup and Toothless grab it in at the last few seconds and put it in Astrid's sheep pile instead of his own. This is similar to what Fishlegs and Snotlout did for Ruffnut at the beginning of the movie.
 * Their relationship officially starts to take form in Dragons: Race to the Edge: Season 4 in the episode "Blindsided", and it was intended to stay secret, however, they were seen kissing by the gang at the end of "Shell Shocked, Part 2".
 * According to an interview with Richard Hamilton; "Hiccup and Astrid lead Berk as a pair by working together as Chief and General."
 *   This was later found to be part of the plot for the graphic novel The Serpent's Heir.
 * Hiccup and Astrid won the 2017 Greatest Couple in Fandom Tournament.
 * There is a Deadly Nadder symbol on the strapline of Hiccup's flightsuit. It's purposely aligned with the position of his heart and is meant to be a nod to his girlfriend Astrid.

Quotes
The page for quotes about Astrid and Hiccup's Relationship is here.