The fact that Derek had the fucking nerve to climb into his window at two o'clock in the morning and wake him up was one thing. It was a whole other story when Derek just stared at him and, without even saying a hello, said the next three words that would practically change Stiles' life forever.

"You're my mate."

"I'm your what?" Stiles chokes on his own words and he has to sit down on his unmade bed, the bed he was previously having a restful night's sleep in until this fucking wolf decided to reveal his feelings at stupid o'clock.

"You're my mate," Derek says again, cocking his head to the side as if he doesn't quite get why Stiles is completely and utterly baffled. "We're paired. You're my match. My mate."

Stiles swallows, his mouth suddenly dry and he licks his lips. "Yes thank you wolf, I know what a 'mate' is, I've done my research on you lot. What I don't get is why me?"

His eyes are sleepy and his body wants to rest, heavy from being woken up at such an idiotic time. He looks at Derek who seems lost in thought for just a moment, before he pipes up to speak once again.

"The wolf inside me chooses someone who thinks is best suited to me. I'm guessing you're it. You're my mate."

Stiles raises a hand and holds it out as if to stop Derek from speaking. "Yeah, I got that the first time you said it, and the second time you proceeded to explain it."

Derek just remains still, his arms crossed over his chest as he watches Stiles intently. Stiles knows that Derek is just staring at him to gauge some kind of reaction, but Stiles isn't exactly sure what reaction he is looking for. He isn't exactly sure what reaction he wants to give.

"Well what does this entail?" He asks shyly. A good fucking every once and again? Will they have to be joined at the hip for the rest of his life? Can Derek just dump him and move onto another mate?

Stiles isn't really sure why he's surprised. Both him and Derek have been intimate with each other before, hell Stiles knows Derek's kinks, he knows the sensitive parts of Derek's body, where Derek gasps at his touch and where Derek likes to be touched more, man he could even draw a detailed picture of his dick, he's blown Derek that many times.

He just never knew it was anything as serious as this. He always thought they were in some kind of "friends with benefits" situation. They'd kept it so secret from the rest of the Pack. They'd fucked countless times in the back of Stiles' jeep (in which Stiles had to keep buying those stupid tree air fresheners so Derek's scent would be covered up, but Scott always sniffed something strange), they'd had sex in Stiles' bed whenever Derek just upped and jumped into his room as if it were his own house and hell, even in the shower a few times. They knew each other's bodies inside and out, but this news shocked Stiles to his very core.

"Don't you like me?" Derek asked, an eyebrow raising. Stiles sighed at the fact Derek was completely ignoring his very important question.

Of course he liked Derek. Of course he liked that stupid chiselled jaw of his that he liked to lick from one side of the other. Of course he liked those stupid abs that he'd bite over and over again until Derek gasped or came or flipped Stiles over so he could do the same to Stiles' not so ab-clad stomach. Why he even liked Derek's personality, when he wasn't being a sour wolf, or a complete and utter ass.

"That's a stupid question," Stiles simply says and steps forwards towards Derek who remains still, "I'm not even going to warrant it with an answer. But you need to answer my question. What does being your mate entail?"

Derek only sighs and reaches out to grasp Stiles' arm, pulling him into his embrace so their chests are touching.

"I'm not going to force you into anything you don't want to do," Derek begins, looking deep into Stiles' eyes and Stiles hates, absolutely hates when he does this because he feels as if he's melting into the floorboards, "I can promise you that. But from what I've gathered, we're bonded."

Stiles looks away from Derek and Derek nuzzles his face into Stiles' shoulder. Stiles knows what he's doing, he's marking his scent.

"Do you have to claim me?" Stiles begins again. He doesn't really know what that means and he hopes to God that Derek does.

"Yes," Derek said, his lips cool against Stiles' neck which fuck Stiles loves, "but like I said, you don't have to be mine if you don't want to."

"What do you have to do to claim me? Is there some witchy satanic ritual? Do you perform a chant and dance around my naked body whilst I'm lifted up into the air like some reincarnated Jesus or some shit like that?"

Derek leans back and looks at Stiles, who smiles as if to say "I'm sarcastic, let me be".

Derek completely ignores Stiles' feeble attempt at humour. "It can be done in many ways. I claim you verbally, but there's also marking."

"Marking? As in a scent?" Stiles has a visage of a dog pissing up against a lamp post. Is he this lamp post? Is Derek going to...Stiles shakes his head at the thought and almost vomits.

He watches Derek who doesn't say anything for a full minute. They just both stare at each other like they're in some kind of no blinking contest, which Stiles seems to lose every time.

Stiles eventually sits down on his bed and thinks this whole, frankly weird scenario over.

Derek's asking him to become his mate. At two o'clock in the morning.

"Wait a second, if I say yes to all this wolf crap, what's the chances that you're not just going to hop-skip-and-run out on me and I'm just left there like some weird widowed wife?"

Derek almost pops a smile, but his face returns to its normal sullen self as he moves to sit next to Stiles.

"It's not like that, my wolf has chosen you. It doesn't want anyone else. You of course as you're a human can choose someone else. My wolf won't choose anyone else, Stiles, you're the only one it wants. The only one we want."

Well that was a speech and a half. Stiles just sits there and doesn't say anything because what the hell is he meant to say? Yes Derek, I'd love to become your mate so we can fuck every day and I'll be yours forever and our little arrangement will become permanent and people will know that we're together and you'll be mine and...

Well actually come to think of it, that seems pretty okay by his terms. However weird and twisted it may seem.

He pushes Derek so the alpha's back is now on his bed, and he straddles his waist.

"So does this mean I get to boss the Pack around?" He asks and Derek laughs and runs a hand up Stiles' thigh, causing an involuntary gasp to erupt from Stiles as he suddenly realises he's horny. Very horny for a teenager at two o'clock in the morning.

"You'd be an alpha-mate, so I guess so," Derek finally responds and suddenly it's Stiles who his on his back and Derek who's on top of Stiles.

A thought pops into his head. "Is Allison Scott's mate?" He asks and Derek nods.

"Scott doesn't realise it yet. I've yet to tell him about it but essentially from what I've seen, yes."

Stiles thinks for a moment. He imagines himself and Derek in Scott and Allison's shoes, and he almost laughs out loud at the fact that he is Allison in this situation.

Stiles is panting with lust now as Derek slowly takes off his shirt, revealing his torso which Stiles nearly faints at every time he even glances at it. He reaches out and traces each ab with his thumb, and Derek flinches from the touch, his lust matching Stiles' as Stiles suddenly feels that Derek is rock hard against his thigh, which only turns Stiles on even more.

"So what you're basically...aaahh...saying, is that if I don't become your mate then you're going to be lonely forever?"

Derek is now reaching down and suckling at Stiles' neck where the pulse point is strongest, and Stiles' hips buck at the very thought that Derek's mouth is extremely talented.

"Don't think of it that way," Derek says against Stiles' cheek and he continues suckling, his hands moving down to lift off Stiles' batman t-shirt.

"Then how else am I meant to think of it like?" Stiles asks, but his mind gets sidetracked as Derek is now licking his chest, so slowly it's almost painful and Stiles can feel his pyjama pants get even tighter under Derek's body. And he knows Derek can feel it because Derek pushes his hips against Stiles' and Stiles wants to howl like a fucking wolf at how pleasurable this is.

Derek doesn't answer, he just continues suckling at Stiles' chest. His hands are now around the waist band of Stiles' pyjama pants and Stiles nearly comes there and then because he can't imagine how hands so soft are attached to Derek Fucking Hale.

Derek bites down on the skin and Stiles completely fucking loses it because Derek knows that Stiles' ultimate kink is biting. He fucking knows. Stiles just moans out loud and he bucks his hips up once more and he's frustrated because he feels the wolf smile against his skin and bite him once again, his blunt teeth not breaking skin but definitely breaking Stiles' sanity. Stiles reaches down and grabs a fistful of Derek's hair and yanks him up so their lips meet in a frenzied bout of passion and lust. Teeth clash together and their tongues fight for dominance but Derek always wins. Derek breaks away and starts licking and kissing from Stiles' jaw, slowly downwards towards his pelvis.

"I don't think you quite know how much I want you Stiles," Derek says against Stiles' hip, nipping at the skin as he starts to pull down Stiles' pants, "I don't think you can quite grasp how serious this situation is."

"Oh I can grasp it alright," Stiles replies as he just lies there, his body a temple of pleasure and frustration and anger and tranquillity, "it would just be nice if you just answered my questions with a straight answer."

"Being my mate does not require you to do anything different; the change is more on my side than yours. But for me that's already happened so it doesn't really make a difference to you."

His pants are off and Derek is biting the inside of his left thigh and Stiles doesn't think he can take this anymore because holy shit Derek Hale is biting the inside of his thigh.

But then Derek stops, and he's back up to claim Stiles' mouth with his and they're kissing and their flesh is touching, rubbing against each other with enough friction that could cause a fire or ten. The fact that his dad is asleep downstairs on the sofa turns him on even more as he has to be quiet and holy crap Stiles can never be quiet when Derek is just there naked on top of him. His hands reach down and fumble at Derek's belt but he's too shaky. Derek's hands reach down and clasp themselves over his and they undo his belt and push down his jeans together so they're now both completely naked, every inch of flesh touching the other.

"I don't think you can quite grasp how the hell you make me feel," Stiles says and Derek growls, he fucking growls and Stiles laughs. "That literally proves my point," and he's arching his back so flesh grinds against more flesh.

"I need you," Stiles hears Derek whisper in his ear.

"You can't fucking say things like that Derek with my dad downstairs I'm going to fucking scream."

The fact that Derek moves his head from Stiles' neck so he's now looking into Stiles' eyes, and he says "that's my intention" makes the teenager want to cry out and touch himself furiously at those very words, but he knows that if his hand even brushes his own dick, Derek will bat it away and say something possessive like "mine" and then they'll end up fucking and it will be all over so quickly. So Stiles stays still and lets Derek do all the work.

But that's proving to be very difficult because his skin seems extra sensitive all of a sudden, and considering Derek is very very nippy tonight, like a new puppy playing with its owner and he keeps flinching at each bite, the quick rush of pain mixed with the pleasure of the pure fact that Derek is on top of him is almost agonizing to his body and to his mind.

"Yes," Stiles finally says and Derek stops stiff, his mouth just about to clasp around Stiles' left nipple.

"Yes what?" Derek asks, his eyes intent on Stiles'.

"I'll be your mate. I don't see it any other way really, I guess it was always going to be you. I guess I've always known, ever since you used to be Mr. McLurker back when Scott was a pup."

"I don't want to force you into anything you don't wan..."

Stiles has had enough and he pulls Derek in for a long and slow kiss, breaking away because it's always him that needs to breathe first. "It's my final answer, now mark me or claim me or whatever the fuck you need to do because I want you to fuck me goddamnit."

"So insistent," Derek mumbles and he smiles and Stiles nearly faints because this man is so beautiful and he still has no idea why Derek would claim him as his own but he has. He feels his legs being lifted and locked around Derek's waist as Derek poises himself at Stiles' entrance.

"What about..." Stiles says and Derek just shakes his head, muttering something about "no time" and instead of reaching for the bottle of lube in Stiles' side draw, uses his own pre come instead as Stiles can tell Derek is just as horny as he is.

The flashing pain of not being prepared enough to accept Derek but it still happening anyway is only quick but Derek fucking strokes his stomach as if somehow it'll relax Stiles and everything will be fine and dandy again. But no, Derek is wrong as it makes Stiles more tense and lustful but Derek's pushed all the way in and he's at the hilt now but he doesn't move.

Stiles shifts his hips as if to say "come the fuck on Derek" but Derek holds both of his hands over Stiles' thighs and just stays there for a while as if he's admiring the view.

"Mine," he growls and he pulls almost all the way out, only to thrust back in again with such force that if Derek hadn't have put a hand over Stiles' mouth, screams of pleasure would be echoing through the house, hell echoing throughout the town and his dad would wake up and all hell would break loose.

Not that hell isn't breaking loose in here. Derek's thrusts are so fast and heavy, so needy for more that it's not long before Stiles is on the edge of his own orgasm and possibly his life because he's never felt anything like this in his life before, not with Derek, not with himself, not anyone ever in this entire universe. He thinks it's impossible that his eyes can roll back into his head anymore but Derek shifts his hips and his that damn spot inside Stiles and not only does he feel the pleasure of Derek being inside him, he's also now experiencing wave after wave of painful desire crashing through his body like a tsunami as he's practically pounded into his own mattress.

It's Derek's low and rumbling growl that eventually sends him over the edge. Derek's not only thrusting but he's also stroking Stiles' dick, his strokes slowly getting faster to meet his thrusts and Stiles is sweating and his entire body is shaking as he comes violently over his torso and Derek's hand. Derek's other hand is now over Stiles' mouth once more and Stiles has to bite into it, and bite into it hard to stop himself from screaming, but this only seems to spur on Derek more as Derek's thrusts increase. Stiles closes his eyes from the pure fact he's absolutely exhausted and he feels the alpha lean down and rest his head in the crook of Stiles' neck, and he's biting on the flesh and then Derek comes just as hard as Stiles did, and the biting is carrying on and Stiles isn't sure whether it's a good or a bad thing that his neck is going to be bruised tomorrow.

Derek is shaking too, his sweat mingling with Stiles' as he just lies on top of him for a while, their breathing in sync. Derek calms down first and he slides out of Stiles, nipping once more at Stiles' body and Derek laughs and Stiles asks why.

"You smell of salt and sex and me and it's the greatest fucking thing I've ever smelled," Derek whispers and Stiles almost comes again there and then.

"Can I consider myself officially claimed?" Stiles manages to breathe out, "although I think I was pretty much claimed from the day we first fucked in the back of my jeep."

"Consider yourself officially claimed," comes Derek's response and he laughs and sucks at Stiles' flesh on his neck but Stiles is just too exhausted to push him off so he just moves his neck to the side to give Derek better access and he just lies there with his eyes shut.

"Is this you marking me?" He asks finally as Derek is now down by his knee, creating a small hickey on the underside.

"You could say that," Derek begins, and Stiles shivers at the cool breath against his skin, "or it could just be another kink of mine."

"I wouldn't put it past you," Stiles replies and breathes out a laugh, but it comes out ragged because he's still panting and catching his breath from what could be the best fucking session they've ever had.

"You look so beautiful when your skin is flushed," Derek says and wow, this catches Stiles off guard. He's never been called beautiful in his life.

"Uh, thanks, I guess," he says and Derek lifts his head up to smirk.

"It's true," Derek begins, bringing himself back up and onto Stiles' body once more, staring down into his eyes, "plus you also have this mouth that looks utterly perfect stretched around my co..."

"Okay dirty wolf enough with the talk," Stiles says and his cheeks flush red with embarrassment and Derek licks each one and Stiles shivers once more, and when Derek rolls off him to lay by his side; he pushes his back up against Derek's torso so they're spooning. His blood feels like it's singing as every now and again he feels a jolt of pleasure erupt throughout his body and it's nothing like he's ever felt before.

He can feel Derek nuzzle into his shoulder and his neck and his back and he smiles, because he wonders how someone who is such an ass during the day can actually be quite warm and compassionate at night. He doesn't question it though, he likes it this way.

"Am I like the mom of the Pack now?" Stiles asks eventually just as he's about to nod off.

Derek only laughs; he says nothing as he breathes into Stiles' hair and exhales slowly, sending tingles up and down Stiles' spine. The fact that Derek doesn't actually answer him kind of worries Stiles, but it's only a moment's worry because he's soon fast asleep once more, and he's kind of happy that he was woken up at two o'clock because this turned out to be a pretty good night after all.