Prompt that has been lying around my inbox for a while.

"Modern. Hiccup knows it's a terrible cliche. He's in love with his best friends girl."

Modern AU, established Justin(Fishlegs)/Heather but naughty naughty Hiccup/Heather. Rated M for sexy times.

I also seem to have had trouble sticking to one tense, so there might be some off-ness in the past or present use of language. Hm.

-HTTYD-

He feels guilty.

Every time he finds himself looking.

Every time he curses that Justin had plucked up the nerve to ask Heather to prom before him.

Every time he tried to tell himself it would all fizzle out.

Every time she looks at him too.

Because Justin is still his best friend, has been since they were kids digging in the dirt to look for bugs. Now they are in their twenties, and Justin and Heather have been dating for five years.

It still rankles.

Hiccup sighs, pushing aside the sketch he is supposed to be working on for his dad - a new logo for the auto shop he runs. He won't get any more done until he clears his head. Running a hand through his messy auburn hair, he wonders if his mother would have any pearls of wisdom.

Probably. But Hiccup will never ask her. He won't ever tell. Justin is his best friend, and Hiccup will suffer a broken heart if he has to for that guy.

He still looks.

Heather was flawless, with her big green eyes and long black hair, that cute braid Hiccup always wants to play with. She was sweet and funny but a total spitfire, regularly terrifying her big brother Dagur with only a glare. She took martial arts, hit the gym with Hiccup three times a week and tortured him by working up a sweat in those black and green yoga pants that haunted his dreams.

Her favourite colour is silver.

She hums when she cooks.

She prefers sunset to sunrise.

She's everything he loves.

And yet, completely unobtainable.

Dagur adores her boyfriend, which is not typical big brother behaviour - Hiccup knows, as he wanted to kneecap any guy that gets too close to his (adopted) sister Astrid. But then Dagur and 'Fishlegs', as Justin is affectionately nicknamed for his oddly proportioned body, are both a little dopey and both love huge, drooling dogs.

Hiccup growled to himself, annoyed for dwelling. He pressed the palms of his hands into his eyes until coloured spots littered his vision and his eyeballs ached.

He took a walk around the streets with his old wolfhound Toothless, hoped it would clear his head.

It didn't.

Toothless had fun though.

He sat back at his desk, staring at the drawing of a car like it would answer all his questions. He added a few lines to flesh out the 3D look of the car, scribbled down a few notes about where and how the shop name would fit best. Then tossed down the pencil again, cursing as he feared the graphite inside would break.

He had managed five years. Hiccup could keep doing it.

Maybe he ought to try and get laid. He could find a girl with dark hair and green eyes... that made him feel gross, using some poor stand in. That was why he had been single for those five whole years - nobody competed with Heather.

The one proper date Hiccup had been on was a set up by Heather, a girl called Cami, though she was better known as Camicazi for her habit of charging into things head first. Their date hadn't been anything special - good or bad - but six weeks later, Cami came out as a lesbian and started dating Astrid.

He didn't have to worry about boys anymore, but that had been awkward. It was still terrifying, as Astrid and Cami were both hot-headed, stubborn and ready to kick anyone's ass. Including his.

Going back to the art project didn't help either, so Hiccup grabbed his riding gear - there was nothing that couldn't be fixed by a jaunt on his beautiful motorcycle.

"Hiccup! Have ya finished my new logo?"

"No dad, I told you I would have it within a week."

"Yes."

"That was only yesterday. You want it done quick or you want it done right?"

His dad raised an eyebrow, scratching at his beard.

"Is both not an option?"

"Stoick!"

Hiccup's mother Valka came to the rescue, swatting at her husband.

"I'm kidding!"

"Of course you are now moms watching. Fishface is at the door for you bro."

Astrid ducked under their dads arm, looking a little worse for wear in terms of alcohol intoxication and grinning drunkenly as she raided the fridge. Sighing, Hiccup supposed his bike ride was about to be interrupted by someone he was trying not to think about.

"Are you alright son?"

She always could tell he was down, even when Hiccup was smiling. He was convinced his mother had superpowers.

"Fine mom."

Grabbing his helmet in a selfish hope that Justin wouldn't take long, Hiccup headed toward the front door and found his friend. Six four and three times Hiccup's width, Justin was the textbook gentle giant. He looked huge and terrifying... until he smiled, and looked about as scary as a teddy bear.

"Hey Fish."

"Hiccup! Oh, am I interrupting you?"

Justin took in his riding gear, the helmet under his arm.

"Depends how long you need me for. I'm not going anywhere in particular."

Justin walked along with him to the garage, Hiccup's black and green motorcycle waiting to take him away from his problems.

"So... what can I do for you Fishlegs?"

"Well, I wanted your advice but you don't seem in the mood so..."

Hiccup shook himself mentally; he was being a shitty friend right now.

"That's not because of you bud, I've been working on my dads auto shop logo all day and... you know what he's like. I'm just winding down. Honestly buddy, what's the problem? I figure it's important or you woulda just called."

Justin considered him for a minute, then brightened.

"Alright then. I uh... I wanna propose to Heather."

Hiccup felt those words like a knife in the gut. How... how was he supposed to watch Heather marry Justin? It... it wasn't fair. But Justin was waiting for an answer, so Hiccup sucked it up. Best friend over broken heart.

"What do you need me for? I'm not doing it for you."

"I kinda hoped you would come ring shopping with me. You got an eye for this stuff."

"Ah, the artists perspective. Sure. I need to finish this work for dad, but if you can wait a couple days I'm all yours."

Justin grinned, looking genuinely happy and Hiccup felt like slime for hating him for it.

"Alright, uh, gimme a call when you're done with the project?"

"Absolutely."

"Oh. And you'll be best man, right?"

Obviously, Hiccup needed a front row seat to the worst day of his life.

"Of course."

"I knew you wouldn't let me down. I'll let you go for your ride, thanks Hiccup!"

"No problem Fish."

Hiccup waited until Justin got in his big orange flatbed truck and trundled off before he punched the wall, fighting and failing to suppress his primal scream of emotional agony.

"Hiccup? You ok?"

Astrid obviously heard something, drunkenly swaggering into the garage to find Hiccup cradling his sore hand to his chest.

"You hurt bro?"

"Its nothing. Banged my hand."

Astrid wobbled on her feet, leaning against their moms car as it was closest.

"Hm. So it has nothing to do with the conversation I just eavesdropped on? I'm drunk, not stupid."

"No. Why would it?"

All traces of drunkenness gone, Astrid fixed him with her big blue eyes that saw all.

"Because you couldn't want anything less than to watch Heather get married to someone else. Did you think I forgot you crying when she went to prom with Justin? We ate three tubs of Ben and Jerrys that night. Mom spent four months asking why you didn't wanna go."

"Astrid, that was like, five years ago."

"So? You still love her."

Hiccup wanted to argue. Hel, he wanted to cry. Astrid was hitting many, many sore spots.

"So what? It hasn't mattered for years. Why would it now?"

"Because you're strong... but I don't think you're up to watching that wedding. I couldn't watch Cami marry someone else."

Gritting his teeth against the urge to yell at his sister - who was brutally right on the mark - Hiccup pulled on his gloves and winced at his sore knuckles.

"I'm going for a ride. Get outta my way."

Astrid sighed, but stumbled clear out of the way of his bike. Shoving his helmet on, Hiccup kicked up the engine and slowly made his way out, checked the road was clear - he didn't want to kill someone because he was in a bad mood - and zipped off from his home, his all-knowing sister and his problems.

The roar of the engine, the speed of the wheels beneath him and the effortless glide through the air... Hiccup loved riding his bike. He left all his problems behind. Nothing mattered, not being in love with Heather, not his best friend, not the fact his sister knew...

He was free.

Hiccup had a half-crazed notion to just keep going. If he didn't go home he didn't have to watch Heather marry Justin. After an hour, he had to stop and refuel his bike, knowing his mother would follow him across the world if he tried to leave, drag him home by his ear and scold him thoroughly.

Astrid was thankfully asleep in an alcoholic stupor when he got back, so Hiccup was safe from the blue eyes of ultimate knowledge. At least for the night. He stripped off his Kevlar-lined leathers, crawled into bed and, after a few loud screams muffled in his pillow, Hiccup managed to fall asleep.

He successfully functioned for the next few days, but once the art for his dad was done, Hiccup had little excuse to ignore his duty to his best friend.

Which found one Hiccup Haddock trying not to throw up as he helped his best friend shop for engagement rings. An assistant watched them peruse cabinets and shelves, then approached.

"Can I help you boys find something? I think we have some autumn inspired jewellery that would suit your boyfriend wonderfully."

"Oh, no!"

Justin protested vehemently, so Hiccup decided to vent a touch of his frustration with some sarcasm.

"Justin, I'm hurt! I'm a total catch."

"Don't start Hiccup. I get enough of that from Heather's brother. I'm here for my girlfriend."

Well, that was the end of his fun.

"I'm moral support. And colour advice."

The assistant watched them, bemused.

"Alright then. What colours are we looking for?"

Justin's mouth bobbed like a fish, so Hiccup took over.

"Silver. Metallic. She's really into the chrome, or futuristic look."

"Ah, then let me show you these..."

They left nearly an hour later after Justin ummed and ahhed and tapped his index fingers together, finally leaving with a platinum and emerald ring.

Hiccup had to give her ring size; Justin forgot it.

"You sure this is the one?"

"The assistant said it brought out my eyes. Me and Heather both have green eyes."

Justin laughed, flicking his eyes toward the store again.

"She liked you. You should go ask her out."

"No way, she spends all day watching happy couples buy rings and imagining her own proposal. I. Will. Pass."

"Eh. I guess. You're a good guy though Hiccup, you shouldn't be alone."

Hiccup wasn't sure that was true - not when he spent so much time wishing he was the one picking a ring for Heather. He only made sure Justin got the perfect one because Heather deserved it.

"Guess I haven't met the right girl. I mean, I met the right girl for my sister, but... I got my bike. I'm happy."

He was lying. Lying so much.

"Anyway, enough about the tragedy that is my love life. When's the big night?"

Hiccup needed to know when he was going to get obscenely drunk.

"Uh, probably this weekend. You'll be the first call I make."

"I've got a new project for a movie concept sketch, so if I don't answer its because I'm elbow deep in dragon scales."

"Don't worry, I know how you get. Thanks for helping Hiccup. You're a pal."

"Mhmm. I better get going."

"Yeah. Me too, I have work tonight."

"Catch you later buddy."

Hiccup hurried to get away, stopping to pick up a decent amount of alcohol on his way in preparation for lamenting the engagement that he should be superbly happy for the people involved.

Despite the plan, Hiccup found he really didn't want to drink that weekend. No amount of Jack Daniels was going to change the fact that any minute now, or maybe tomorrow night, Justin would be down on one knee with his Fish-legs, popping the question Hiccup had dreamed of asking Heather for years, with the ring he picked out.

"Here if you need to talk bro."

Astrid knew, but she wasn't pushing it. He appreciated that. Adding a few scales to the drawing he was working on, Hiccup had half a dragon. It wasn't going to be finished that night, but it was only a concept. Even if the movie took it, it would be altered and tweaked and animated... it wouldn't be Hiccup's dragon any more.

His phone buzzed again, but Hiccup ignored it. He had already given Justin an excuse to why he was being ignored. Hopefully he could put off ending his denial until tomorrow. The vibrations didn't let up, and when Hiccup eventually glanced across, his heart skipped a beat when he saw the name on the screen.

Heather.

Scrambling to pick it up, Hiccup clicked answer just before it cut out.

"Hello?"

"Hiccup! Thank Thor you answered, I didn't know who else to call."

"Is everything alright Heather?"

Gods, he loved her voice.

"I, uh. I don't wanna talk on the phone. Are you busy?"

Hiccup looked across to his half-done drawing.

"No. You wanna come over?"

"Can you come to me? I think I'm too drunk to drive."

"Uh. Ok. You at your place or your brothers place?"

"Mine."

"I'll be fifteen minutes."

"Thank you."

Hiccup hung up, concerned about why Heather was drunk and alone. Surely Justin should be there? It was lucky he hadn't been drinking, it would have taken nearer an hour to walk to Heather but now he could drive there.

He changed and hopped on his bike, trying not to break the speed limit in his haste to get to the girl he loved. Heather's flat was sort of welcome, sort of hell. It was so her, but it would never be somewhere he could be truly at home - Justin could be, they were planning on moving in together.

Heather buzzed him in, opening the door before he could knock and he was rather upset to see her eyes were red, on top of her saying she was drinking.

"What's wrong?"

"You want a drink?"

"No, I want to know why you're in such a state."

Hiccup took off his jacket, ignoring that way Heather's gaze lingered on him for a half-second longer than it should.

"I think Justin's gonna propose. He's been acting shifty, checking my schedule."

Given his personal knowledge on the subject, Hiccup knew she was right.

"And that thought made you cry and get drunk?"

Heather shrugged, fiddling with her ebony hair braid that Hiccup wanted badly to unwind and feel her hair run between his fingers.

"I feel like... not that it's too fast. We've been dating forever. Just... too soon? I'm twenty one! It's not normal to be thinking about marriage at this age. It scares me. I lost my virginity to Justin, I literally know nothing but him."

Heather must be emotional - she never talked this way usually.

"I thought that was a good thing. Finding your dream guy and all, high school sweethearts."

He made himself sound supportive, not cruel and jealous as he wanted to, as he really felt.

"So did I. I just... I don't know, maybe I'm being silly about all this. It's just a surprise."

Hiccup noticed she didn't ask - Hiccups lack of denial meant she was pretty sure she had been on the money. Swallowing his personal desires, Hiccup did his best to be a comforting friend.

"Come here."

Heather crawled into the offered hug, still sniffling a little. Hiccup's heart spasmed painfully, but he focused - good friend over broken heart.

"Do you love Justin?"

"Of course I do."

"Then stop worrying about it. Have a long engagement. Justin won't mind."

His hand took on a mind of its own, playing with the loose hairs at the side of Heather's face. She didn't stop him.

"I know."

"You two love each other. He just wants to make that official. Don't think about being too young, too soon. Just think about how much you love him."

She had better, because Hiccup was carving parts of his soul out to offer this advice.

"You're right, I know. Just... a little too used to my independence now."

Heather and Dagur had lost their parents in an accident three and a half years back, so they had gone students to full-blown adults in a heartbeat.

"And Justin knows that. If you wanted to wait ten years to get married, he wouldn't argue. He just wants to show that he wants you forever."

Heather sighed, settling against his chest and Hiccup couldn't help but inhale a breath full of her light, sweet scent. He could smell cocoa... she had been baking. Humming and bouncing around the kitchen while she cooked.

"You're right. I lost my head for a minute. Thanks Hiccup."

He smiled tightly, heart fluttering in his chest when Heather turned around and touched her gorgeous lips to his cheek. There was no way Heather didn't hear his breath hitch, couldn't feel him shake as the front of her body pressed against him. This was cruel.

And yet, beautifully so.

"You ever wonder Hiccup" she spoke the words against his cheek, warm and moist against his stubble "how it would have been?"

"Uhh" he almost forgot how to talk "how what would have been?"

"If you'd asked me to prom. It was you I held out for, turned down a dozen guys" wait, what was she saying "but then Justin asked me, and I figured if your best friend was asking me, you weren't going to."

"I wanted to. I was just too awkward. And then"

"Justin beat you to it."

"Seems like it was the right thing to happen. You guys have been together ever since."

Heather hadn't moved, and Hiccup was struggling to breathe properly as she slowly saturated each and every sense of his. All but taste. She was inches from his mouth, it would be so easy...

"Yeah, guess so. I still wonder sometimes."

Hiccup swallowed thickly, deciding he needed to move now before he cracked.

"Heather... you shouldn't."

"I know. I shouldn't do this either."

Her hand grabbed his collar, pulling him in and Hiccup finally knew what it felt like to kiss her. Her lips were soft and warm, but Hiccup realised beneath the chocolate on her tongue he could taste alcohol.

She was drunk.

He couldn't do this.

With all the willpower in the world, Hiccup pulled away.

"Heather, no. You're drunk, and you're dating my best friend."

She didn't move, hand still fisted in his t-shirt as those huge green eyes fixed on him.

"I had one drink. I lied about being drunk to get you over here. If I'm gonna agree to marry Justin tomorrow... I want to know what I missed out on."

Heather kissed him again, boldly straddling his lap and Hiccup lost himself in the way her hands clutched in his hair. It wasn't sweet or romantic or any of the dozen things Hiccup had dreamt of when he guiltily pictured such a moment.

Her small hands grappled at his zipper, further proof of her pre-planning evident when Heather leant behind him, holding a condom. Hiccup had never been one for rushed and frantic, he wanted to appreciate the moment.

"Whoa, slow down Heather."

"Can't" she bit his lip, gasping as he grabbed her thighs "if we slow down, I'll think too much."

His libido and his conscience were at war - Heather wanted this, but she only wanted one night, one time and then she would go back to Justin. She would know Hiccup could never say anything, not without breaking his best friends heart.

Heather was using him, wanting a last moment of freedom before she accepted Justin's proposal of marriage.

And Hiccup was pathetically, desperately in love with her enough that he would let her.

She moaned against his mouth when Hiccup reached beneath her skirt, finding only bare skin and his cock twitched as he found her wet, hot and ready. He stroked her clit, determined to get as much out of it as he could since Hiccup knew this would only ever be for one night.

Heather tore open the condom packet, rolling it over his shaft and holding his gaze for a minute. He could still stop her, stop this before it went too far.

He didn't.

An awkward fumble later, Hiccup was inside her and it was everything he had dreamed of. The girl he loved, soft and welcoming around his cock and moaning hotly against his lips with pleasure. Placing a hand on her lower back, Hiccup turned them, laying her across the sofa properly and feeling her clutch at him for stability.

"Justin waited four months for this" Heather breathed the words between thrusts, between needy whimpers in the back of her throat "because I was mad I didn't get prom night with you."

"That supposed to make me feel better?"

"No."

The mood shifted; they weren't having sex anymore. It was a fuck, primal and primitive and emotionless for a cold dose of reality. Hiccup didn't stop; it had been too long and he would never get this chance again.

Heather still responded, moaning and bucking her hips, nails finding the skin beneath the back of his t-shirt and scratching it. Drawing blood. Hiccup returned the favour, sadistically enjoying that she would have to hide them from Justin, the tracks of Hiccup's touch on the delicate skin over her hips.

He stilled, watching her writhe and wriggle, trying to get him to move.

"Take off your top."

She complied, awkward and difficult as she was laid down but eventually the material came off, giving Hiccup the view of her bare chest. He leant down, sucking a nipple into his mouth hungrily and tasting her skin as he thrust again. Heather thrashed, moaning and digging her fingers roughly into his scalp. Hiccup let her feel teeth, not enough to hurt but just enough that she would feel it later.

If he had his way, slamming their hips together with no finesse now, only brutal force, Heather would still be feeling him tomorrow. Aching between her thighs as Justin plied her with romance. Remembering how she begged him for more, arching her back and gasping his name as Hiccup pinched her swollen nipple.

He was gonna come too fast; he needed this to last longer. Hiccup gripped the base of the condom, pulling out. Heather whined, protesting.

"You're not done already?"

"No. Turn over."

Heather scrambled to comply, bracing herself on the sofa arm as Hiccup yanked down her skirt, leaving her naked but leaving it pooled round her knees so she couldn't widen her legs. It meant when he pushed back in, Heather stayed tight around him. He grabbed her ass because he could, squeezing hard enough to leave a handprint.

She almost sobbed when he thrust again, pushing back to meet his thrusts and her ass clashed with his hips brutally, beautifully. Leaning forward, Hiccup braced his weight with one hand next to hers, the other sliding around her slim hips to rub her clit. It was hot and slick beneath his fingers, drew the most exquisitely pleading moans and whines from her mouth.

"Fuck I'm gonna- uhhh, gonna come."

"Say it."

He wasn't going to last much longer; Hiccup wanted to come hearing her call his name.

"H-Hiccup!"

It sounded ridiculous, his stupid name, but it also sounded perfect on her tongue and as she spasmed around him Hiccup buried himself as deep as he could and came. Heather kept trembling, climax spreading out as they both rutted and quaked, sharing in the forbidden pleasure.

The rush eased. As the reward hormones leeched away eerily fast, Hiccup was left feeling nothing but guilt.

He pulled out, watching Heather roll over and collapse naked against the sofa, limbs still a little shaky.

"I have to go."

Hiccup all but leapt off the sofa, doing up his bottoms and grabbing his jacket. There was blood on his lip where Heather had bitten it, spots of blood on his back where she'd scratched him.

"Hiccup."

He turned, not really wanting to look at Heather right now.

"What?"

"You can't ever tell him."

"I won't tell anyone."

He left.

The ride home felt ten times longer, and Hiccup crawled into the shower feeling dirty, disgusted as he flushed the condom still on him. He'd betrayed his best friend, and for what? That encounter with Heather had been sickening in it's cold, unfeeling baseness.

No. All it had achieved was a fresh wave of guilt, another secret to keep from his best friend. Hiccup turned off the shower and dried himself roughly, skin stinging with rough treatment. He put on pyjamas, burrowed into his bed and cried.

Hiccup skived off his work the next day, finally partaking in the alcohol in his room and successfully being drunk by midday. Astrid sighed and brought him food, tissues for when he started crying and managed to fend off nosy parents in the process so he was mostly left alone.

"Was it worth it?"

She didn't need to ask more; Astrid could practically read his mind.

"No. Not at all."

She should judge him, hate him. Instead, Astrid wrapped a blanket around his shoulders, rubbed his hair soothingly and subtly removed the rest of the alcohol from where he could reach it from the prone position he'd taken on his bed.

His phone rang. Astrid peered at the screen, grimacing.

"Fishlegs."

"That'll be him telling me she said yes. Answer it for me? Say I'm asleep or dead or something?"

Astrid sighed, but picked up the phone and answered it.

"Hey Fishface. No, he's asleep. Burned himself out on his latest project."

Hiccup never loved his sister more than in that moment.

"Mhmm. Oh, congratulations. Yeah, I'll tell him. Enjoy your night."

Astrid tossed his phone aside after hanging up, giving him a sad sort of look.

"She said yes."

"Yep."

"Knew it. Oh well. Maybe I'll take up beekeeping, or collect snakes. Bachelorhood isn't so bad."

"I'm gonna get you some water, then you're going to go to sleep."

"If you say so mom."

Astrid rolled her eyes as he began to slur more from exhaustion, bringing him a bottle of water and encouraging him beneath his bedcovers like a mother would a little boy.

"Thanks Astrid."

"No problem bro. Sleep."

She kissed his forehead, then left and turned out the lights. Hiccup fell into a fitful sleep, waking up with a rotten hangover. That could be fixed with a hearty breakfast, a shower and some paracetamol.

The emotional hangover of Heather and Justin getting engaged however, would not be dealt with so easily. Hiccup cleaned himself up, fixed on a smile and grabbed a bottle of wine before heading over to Justin's house. Heather answered the door, ring on her finger as she gave Hiccup an utterly awful look.

"I hear congratulations are in order."

"He's out back. Remember..."

"Never tell. I know. I won't."

Heather stepped aside to let him in, her own smile fixed in place as Hiccup headed through to find Justin. He congratulated his friend and reaffirmed that he would be best man, nausea cloying his senses. Dagur was ecstatic, elated and bouncing around in joy for the future brother in law. Hiccup was trying not to cry.

When Justin was marrying her and heading off for the 'wedding night', Hiccup would be drunk and alone and remembering how Heather looked writhing beneath him.

But it didn't matter.

He would suffer a broken heart for his friend.

-HTTYD-

This in no way bears anything on my opinion of Fishlegs - I adore him, he's big and dopey and loves books and dragons.

I loved that they took Heather, this proper 'dream girl' and went yes lets pair her with the geek.

But hey, a prompt is a prompt and I wanted to step outside my comfort zone today.