I didn't even write this. Gotta love an accidental collaboration where someone is like "I WROTE YOU A CHAPTER!"

-HTTYD-

The next morning was... weird to say the least. Last night, Hiccup had asked her whether they were ok and she'd assured him they they were good. And they were. They were good, amazing. Gods, they'd been amazing together... but to say that they were the same as before certainly would have been a lie.

The difference... it was everywhere! In the way she woke between her brothers, feeling the heat of their skin against her own. How sleepy cuddles had turned into sleepy morning sex without so much as a blink. Astrid felt a pleasant little quiver at the memories of that.

It was in how their kisses had left her dizzy when they should leave her horrified. But it was also in the sudden awkwardness she felt when she had to borrow Hiccup's clothes to go back to her dorm, the sense of 'walk of shame' never having been part of wearing his things before. It was in the shy but clearly not brotherly kisses they gave her when she was about to leave. And it was in the way her hands shook as she accepted the strong coffee Eret had brewed for her, knowing exactly how she liked it but never having done it when she was tired after a night of heated sex.

Gods, she'd had sex with her brothers!

"Oh, wow! Look who finally got sufficiently laid!"

Astrid winced as she was greeted by Heather's excited outburst. It was still early in the morning, but with everyone having courses again, half the dorm was up already. Shit! It only took a second or three before she was surrounded by her new friends, everyone demanding details. Where, how, who? Astrid felt a sense of panic rise inside her as she tried to dodge one question after the other. She couldn't tell them where she'd spent the night or with who. Nobody could ever know! But she should have known that keeping everything a secret was impossible.

"Oh, I know that shirt," the brunette from four rooms down the corridor suddenly exclaimed, and Astrid froze. Shit, shit, shit! "Yeah, no doubt. That black t-shirt with the curled-up dragon on it? I sure have seen that one before."

The others shared a surprised but knowing look, then turned to inspect Astrid more closely.

"You're right!" Dagur chimed in, giggling. He leaned closer and sniffed at Astrid "there's even that scent. Leather and sandalwood. Mmh, I'll never forget this one."

"Woah, lucky Astrid! Where did you meet the twins?"

Someone else asked, using the kind-of-official nickname her brothers had gotten. There were other twins at the university, but generally, someone asking that meant Hiccup and Eret.

"Isn't Monday usually one of the days they stay at home?"

Damn, even their weekly routine was known?

"No, I didn't meet the twins," Astrid denied vehemently, turning her head away from everyone as she tried to push past them "and now I need to get my things. I actually attend lectures."

There were murmured protests as Astrid left the others behind her, but she didn't care. Nobody could know what had happened, not ever. Once in her room, Astrid leaned back against the closed door, fingers running through her hair as she tried to calm down. Nobody could know, nobody could know, nobody-

A sharp knock against her door made her yelp, then it got pushed open before she could even react. Without a word but with a meaningful look in her green eyes, Heather slipped inside. She closed the door again, then crossed her arms in front of her, her foot tapping impatiently.

"So?"

"So what?"

Astrid asked, not really understanding the question. Sure, Heather probably wanted to talk about Hiccup and Eret too, but about what in particular, Astrid had no idea.

"Why are you denying the obvious?"

"I'm not! I-I didn't! I mean…"

Astrid trailed off, once more running her fingers through her hair. Gods, this was a disaster.

"Astrid, dear, the others are right, you know? Even I know this particular shirt, and I believe my brother when he says he recognised the scent on your hair" that was such a weird sentence, Astrid might have laughed in less dire circumstance "and let's not even talk about that look on your face when they mentioned the twins. Honestly, it couldn't have been more obvious, not even with a neon sign over your head or them having signed your tits. So, I'll ask again. Why are you denying the obvious?"

Under the pretense of searching for her books, Astrid turned away from Heather. Shit! She knew. Everybody knew. And her trying to keep it a secret had only made it more obvious. What would happen now? Would they report them? Was one illegal night spent together enough to get them all into prison? What would their parents think?

"Is it because of me?"

Heather's unexpected question made Astrid pause, her mind stumbling. Confused, she turned to look at Heather again.

"Because of you? Why would it?"

With her arms now wrapped tightly around herself, Heather looked a bit uncomfortable.

"Because they apparently are avoiding me," she muttered. "I mean… we see them regularly at the parties we go to, and it feels like everyone hooked up with them by now. Everyone but me. I mean, I don't think I look that hideous or whatever, and I usually get what I want without them well enough, but…" she shrugged, biting her lip as she averted her eyes "well, it stings a little. But that's no reason for you to pretend you didn't hook up with them, especially not if it's that obvious."

Astrid wasn't sure what to say to that. It was on her request after all that Hiccup and Eret stayed away from Heather. She'd never thought that would have any impact on strong and confident Heather… But apparently, Astrid had indirectly hurt her friend, and right now, she seemed to hurt her even more by trying to hide the obvious.

"You're right," Astrid slowly admitted, making a probably stupid snap decision in her mind. "I… I did spend the night with the twins. Sorry, I didn't want to rub it in."

Maybe admitting that she'd had sex with them wasn't the wisest thing to do. But it certainly was better that trying to hide it. Or even to tell the whole truth. And judging by Heather's honest smile, it had been the right thing to do.

"That's alright. I kinda appreciate the concern, but there's no need. I'm a big girl and can live without a certain pair of cocks in my life. But now, tell me all the juicy details. Are they really as fantastic as everyone says?"

Sighing in a twisted form of relief, Astrid nodded.

"They are. Gods, I've never had sex like that before."

For a couple of minutes, Astrid kept on taking, filling Heather in on the details she felt safe to share. It felt good to talk about it, to admit the joy she'd felt while having sex with her brothers. Even though there wasn't a single thing in her life she'd ever felt so torn about.

Because it didn't shock her, and if she was truly honest with herself, then that fact didn't even surprise her. Because there had been a time, when she'd been twelve or thirteen, where she'd harboured an ill-advised crush on her older and quite good-looking brothers. Because pretty much every girl (and quite a few boys) in her school had had a crush on either one or both of them, which had made Astrid strangely jealous. Because they were her brothers, and not theirs.

Oh, she had seen the irony in those thoughts, had pushed them aside and had buried them beneath logical reasoning. They were her brothers, and her fantasising about them in the way others did had been wrong. For six years, those logical reasons had been enough to keep the misdirected longing and fantasising at bay.

Until Heather had mentioned that gods-damned possible threesome.

And now that it had happened, she knew that she wanted more. No matter how wrong it was, how illegal, how sick and twisted - she'd loved it, every single second. Their hands and mouths all over her, feeling their strong muscles beneath their heated skin, hearing them utter her name in that filthy tone, tasting them, feeling their strong and sure thrusts… she'd loved it all, and the mere thought of never doing it again, made her feel hollow and forlorn.

No, so long as Hiccup and Eret were on board, they would definitely do it again. And somehow, Astrid doubted that her brothers would complain about that.

With his arms crossed in front of him, Hiccup gazed at the door that had just closed behind Astrid. His thumb was tracing his lips, still tingling from their kiss just moments before. Odin, had that really happened? All of it? It felt like too much to wrap his head around.

"So, was it how you imagined it would be for you?"

Eret's question and the mug he held out to him tore Hiccup out of his thoughts. In an attempt to buy time to think of an answer, he reached for the tea and took a careful sip of the hot brew, wincing as it burned his lips but somehow not really caring. He could still feel Astrid there.

Had it been like he'd thought it would be?

(Six months before)

"So, what are we going to do?"

Eret placed his phone back down onto the sideboard, and glanced at Hiccup sitting on the sofa. It was a strange look, rather unconcerned despite the news they'd just received. Astrid had gotten accepted at the same university they visited too, and in only two months time, she would move here as well.

"The question is what can we do?"

Hiccup muttered in response. Eret, however, seemed to be unperturbed.

"'Hey, sister dearest. It's so good to have you live nearby now. But before you hear the odd rumour, we've got to tell you something. Something you can't tell mom or pops! The thing is, Hiccup and I fuck, regularly, for almost ten years now. Every now and then, we also invite others to join us. No, they don't know we also fuck each other, but it's fun. We're only telling you because you're our sister, and we wanted to ask you whether you'd want to join in.'"

Hiccup threw Eret a dark look that only caused his twin to burst out laughing.

"Is this a joke to you? We can't tell her that. She… she'd freak!"

Chuckling, Eret came over to sit down next to him.

"Hey, we're sexy. I'm not sure she would say no" Hiccup could only roll his eyes, because Eret really was ridiculous "but you're right, that's not what we should tell her on a 'Welcome To University' card."

Hiccup somewhat relaxed again, even though Eret's words had conjured up a warm tingling in his belly.

We wanted to ask you whether you'd want to join in.

Oh, Eret was an ass. Well, he had a great ass, but he was also an ass. Because he knew that the thought alone of Astrid joining them in their not-quite-acceptable free-time-activities would make Hiccup's blood boil hotter. Sure, they both had always felt that odd pull toward their sister, part curiosity, part forbiddenness, and part that she was just hot. But over the years, Hiccup's interest had grown stronger. Or maybe Eret was just better at hiding it and too fond of teasing him. Who knew? Either way, the thought of Astrid moving here to uni, to be so much closer, to inadvertently learn something about her brother's lifestyle made him... nervous.

"Come on, H. Relax. Let's think about it" Eret eventually went on, a little more sober now. He was quiet for a minute, then nodded as if to himself "okay, I'd say you're right. The question is 'what can we do?'. Because, yeah, we can't just drop the whole bomb on her. But fuck, H, I don't want to lie to her either!"

Feeling his throat tightening, Hiccup nodded.

"Agreed."

"So, I'd say we tell her… well, we tell her nothing. But in the event it comes up, cus she's bound to encounter someone we've fucked, we be honest if and when she asks a direct question?"

Gulping, Hiccup nodded again.

"Yeah, that sounds reasonable. And… and how do we treat her? I mean, what do we want from her?"

At that, Eret started to laugh again.

"Oh, I don't know? What do we want from her?" he turned to face Hiccup directly, an insinuating smirk all over his tattooed face. Again, Hiccup glared at him and again, it didn't really affect Eret's mood "well, let's see. If we assume consent and willingness and everything… then I'd like to see her riding me. Damn, with her fierceness, she'd be amazing to watch. I can almost see the fire in her eyes already. And I want to watch her giving you head. Because honestly, watching you getting oral is great, and if it was her? Bonus points!"

Hiccup was still glaring at Eret, but he knew very well that his expression had lost even the last semblance of severity.

"You're not helping!"

He almost whined as the pictures Eret had drawn with his words were forming in his mind. The idea of Astrid…

Almost aggressively, Hiccup shook his head. No, he wouldn't think of his little sister that way. Not again. But Eret knew him better than any other person on this planet.

"I say we treat her like we always have," Eret sighed "she is our little sister, nothing more. We show her around, help out when she needs us, but let her live her life and make her own choices. Assuming that… that she's like us would be foolish, even if I'd certainly like that. Nothing really changes by her moving here. We'll just see more of her."

Damn, Hiccup hated it when Eret used logic on him! Usually, it was the other way around, using his own weapon against him wasn't fair.

"Agreed."

He muttered again, and actively pushed aside everything else that popped up in his mind. The regret over having to accept this as the only sensible solution. The wish to just treat her like he would every other girl they'd meet at a club or bar, leaving the choice to her but at least letting her know that there was a choice. The fantasies about-

No!

Forcefully banishing all thoughts about that from his mind, Hiccup took a deep breath before slowly letting it out again. She was their sister. Their sweet little baby sister. They had to look out for her, make sure nothing happened to her. That was it. End of story!

"All right, then we know what to do," Eret said cheerfully, and made himself more comfortable, reaching over to place a hand on Hiccup's thigh "and now that we've decided on what's the right way to behave, let me hear about what you'd want. Just for the fun of it."

Groaning, Hiccup let his head fall back against the headrest. His twin was horrible! But also horribly insistent with his talented hand moving up his leg, which was awfully distracting.

"I… I want to kiss her," Hiccup heard himself mumble as he gave in to the sensations Eret easily elicited with years of practice "like that weird boyfriend she had back then, pressed against a wall, holding her, tasting her skin, her neck, and - fuck, Eret that's not-"

"Not fair?" Eret chuckled, leaning to bite playfully at his throat before continuing "I'd say it's highly entertaining. Go on, I want to hear more."

With only a few quick and practiced motions, Eret relieved them both of their already limited clothes. He pushed Hiccup down into the sofa's cushions, and saying that Hiccup didn't enjoy the familiar slide of skin would have been a lie as scrabbling fingers grabbed the lube stashed nearby. They often ended up fucking pretty much anywhere.

"I-I want to hear whatever filthy sounds we can draw out of her when we team up on her," he gasped as Eret toyed with his already fairly loose ring of muscles, having only been inside him yesterday "I want to go down on her, learn how she tastes, whether she likes it better rough or sensual or b-both!I want to know how she feels, her breasts and nipples, her skin, her hair. Gods, her ha-aaahh! I want her scent stuck on my skin, I want to taste her on your- gods, Eret!"

Hiccup knew Eret liked to hear him talk, but - fuck - that was hard to hold up with two fingers stroking his prostate, Eret's unerring precision enough to almost completely ruin his brain.

"And I'd want to know how she feels around me," Eret went on when Hiccup could speak no more, even his brothers thoughts starting to trip and stumble over the other in the heady haze of lust "I want to make her scream into the cushions, want to see that lithe body tremble and shake. Is she loud when she comes? I bet she bites... Gods, can you image it, H?"

Hiccup could only make a pathetic whimpering sound, the combination of those fantasy images and the very real sensation of his twin pressing into him too much for him to form any sensible words anymore. Eret seemed to fare little better, his movements quickly becoming more urgent and his uttered fantasies turning into unintelligible grunts and groans. Hiccup was happy either way, only focusing on the sensations and clutching at Eret's shoulders when his brother reached down to stroke his cock, pumping in time with his own thrusts. It was perfect, the movements learned and familiar. Eret knew just how to get to him, knew how to leave him nothing but a trembling mess eager for the impending relief. They knew each other so well, knew everything...

And yet, Eret managed to surprise him. Hiccup was close, could already feel the familiar tightening in his lower belly, the heat. It wouldn't take much more now, just a couple of strokes and thrusts, just-

Eret leant down and brought his mouth to Hiccup's ear, husky whisper rough against his ear.

"Imagine Astrid were here now. Imagine her watching us - and enjoying it."

Hiccup came with a scream, the force and suddenness of his climax completely taking him by surprise. In that moment his vision turned white, his orgasm tearing through him like an explosion, and the only thing he could see was the image of Astrid in his mind as his body buckled.

Only slowly did he find his way back to reality. Apparently, Eret had pulled out rather than coming inside him because, surely, the mess that covered his stomach couldn't be all his, right? Even as violently as he'd- yes, Eret was kneeling over him, panting through the last waves of his orgasm with his hand around his cock. Hiccup let his head fall back, and they both took a moment or three to catch their breath - and to work through what had just happened. Because it was one thing to harbour a misplaced crush on their sister, but a completely different one to actively fuck while fantasising about her… right?

Despite the rush of reward hormones flooding his system, Hiccup felt numb, and it only took one exchanged glance to know that his twin felt the same strange emptiness aside the bliss. What were they supposed to do?

"This doesn't change anything," Eret muttered after they'd cleaned up and were dressed again, heavy arm slung over Hiccup's chest as they lazily snuggled. Hiccup threw him a doubtful look, but Eret just shrugged and scratched his tattooed chin in thought "I mean it, it doesn't. How we feel can't change how we treat her."

In a strange kind of way, seeing the smugness wiped off Eret's face was a relief to Hiccup. So he wasn't alone in this, Eret felt just like him. But he was also right. If Astrid initiated anything, they would be eager to accept, but it would have to come from her. Their feelings couldn't affect their behaviour toward her. They just couldn't.

(present time)

"No," Hiccup murmured in a belated reply to Eret's question. It made Eret perk up in surprise, but the smile playing around Hiccup's lips seemed to appease him "no, it wasn't like I imagined it. It was so much better!"

Eret gasped out a short laugh.

"Yeah, I agree" he paused, chewing his lip and oh how it reminded Hiccup of Astrid "gods, I… Well, this went much better than I thought. I mean, sure, there's a lot of talking that needs to be done, but... damn, H…"

Eret paused again, but this time, it didn't seem as if he was going to continue. Hiccup used the moment to take a sip of his by now slightly cooled-down tea.

"I know what you mean, Ret. This night blew up even the wildest fantasies I dared ever imagine."

Involuntarily, his hand wandered to his chest where, next to the tattoo they all shared, a prominent bruise was forming. Astrid had left a mark on him, on them both, but it was way more than just those physical ones.

"What are we going to do now?"

Hiccup broke the silence, though the question floated between them for a moment, neither willing or able to answer it until Eret sighed.

"Well, I say we do what we always did. We roll with it. To everyone who wasn't here last night, nothing has changed. Nothing can have changed!"

He shrugged a little helplessly, and Hiccup nodded. But deep down, they both knew that Eret was wrong.

Last night had changed everything.

-HTTYD-

N'awh, look at them all being terribly naughty with their crushes.