When they first got together, Derek told Stiles he wasn’t going to seep with him until he turned eighteen and soon the ‘sleep with’ rule turned into doing anything sexual. He’s no stranger to breaking a few laws here and there but Derek doesn’t want to break this one, doesn’t want to get arrested for giving whatthey see as a harmless blowjob. The state of California will see it as something else, as statutory rape or some crap like that, so Derek tells Stiles to keep it in his pants.
So, for half a year before Stiles’ eighteenth birthday, all they do is make out. Sometimes there’s rutting, thrusting against each other like two hormone crazed teenagers, and Derek usually comes in his jeans like he’s seventeen all over again instead of twenty-five.
But soon it becomes too much and Derek starts ticking off the days on a calendar. Literally ticking them off with a permanent marker, waiting until he gets to the day he circled — three times — in red ink: April 8th. On the inside of he box, he wrote "Sex Day" and laughs every time he sees it because he was kind of going nuts with hormones when he wrote it.
The day finally comes but Derek still has to wait. He knows that Melissa and Sheriff Stilinski have taken Stiles out to dinner, have been spending time with him, so he waits in his loft until he hears the familiar sound of the Jeep’s engine pull up outside of his building.
Derek waits and he’s already hard, has been for a while, so he palms himself. Watches the door, grips his cock through his jeans, and waits. Finally, the door opens and Stiles steps in wearing what the Alpha would call ‘formal wear’ — a pair of khakis, a black button down shirt with the sleeves rolled up around his elbows, and a pair of boots.
And it’s a sexy outfit, especially on Stiles.
"It’s my birthday," he says, grinning as he shuts the door behind him.
Stiles laughs and hums as he walks forward. “That’s right,” he mutters, “I forgot you circled it a thousand times on the calendar.”
"That was just so I didn’t forget," Derek argues, but he turns pink.
When Stiles gets close enough, he straddles Derek’s lap and slips his hands into the older man’s hair, tugging him forward for a kiss. He presses their mouths together and Derek makes a noise against Stiles’ lips, bringing his hands around to grip the teenager’s ass. His cock is so hard it’s almost painful and he wants to tell Stiles to forget about the foreplay, to just get on with the actual sex part.
The kiss is broken and Stiles whispers, “I get whatever I want, right?”
"So… you’ll let me fuck you?"
Derek’s breath catches in his throat and he groans, letting his head fall back against the couch as he thinks about that. They’ve never talked about Stiles fucking him, just the other way around, but he has to admit that the thought of the teenager’s cock sliding into him is rather appealing.
"Is that a yes?" Stiles questions.
"As long as we can cut through all the foreplay and just fuck," Derek agrees, nodding his head slowly as he swallows, his Adam’s apple bobbing.
A groan escapes Stiles’ throat and he runs his fingers through Derek’s hair slowly, nails scratching along his scalp before they’re gone. And if the Alpha lets out a whine at the loss, he doesn’t pay attention to it and Stiles doesn’t acknowledge the noise.
"Come on, we’ll do this in your room."
"Why can’t we just fuck down here?" Derek asks in a quiet, somewhat annoyed voice.
Stiles snorts and climbs off Derek’s lap. “Because,” he starts as he undoes his shirt, “I want to have sex on the bed and not on your lumpy couch.”
"My couch isn’t — "
"Oh, yes it is." Stiles interrupts him easily and Derek just narrows his eyes, watching the teen’s lithe fingers move down the trail of buttons. They move slowly and with much more grace than Derek’s ever seen Stiles possess before and he suddenly imagines the digits pressing inside of him.
A moan settles low in his throat and Derek nods, shedding his Henley. It gets tossed somewhere onto the floor, soon to be forgotten, and he undoes his jeans while he’s sitting down. He sighs in relief and watches Stiles peel the black fabric away from his skin, reveling perfectly pale, smooth flesh that’s dotted with moles. Derek wants to run his tongue all over the boy’s torso, wants to connect each and every mole with his tongue.
"Up," Stiles says, holding his hands out and Derek nearly snorts at the command. It sounds like something he’d say to a dog - or a child - and even though every part of his body is telling him not to obey, he does.
Derek slides his hands into Stiles’, slotting their palms together, and stands. He drops one hand down to adjust himself and groans, the pressure building in his body. If he doesn’t come soon, he thinks he might just explode and won’t that be fun?
Without another word, the pair move toward the spiral staircase. Stiles leads Derek up them, occasionally squeezing his hand or himself and the smell of arousal is thick and cloying in the whole loft — but Derek loves it. He knows that the whole place will stink of sex and sweat and come for days and it makes him whine.
"God," Stiles laughs, "you’re so impatient."
"And you’re not?" Derek clenches his jaw, nearly stumbling over his own feet when they get to the top of the stairs. Yeah, trust him to be the nervous one this time. Maybe he and Stiles swapped bodies or something because, for the first time, the teenager seems oddly cool and collected.
And kind of smug, but that’s a given.
Stiles shrugs his shoulders and pulls Derek over to the bed. “I’ve been impatient for years, dude,” he says and sits down on the edge of the mattress.
"Then why are you acting so… calm?" Derek breathes the words as he looks down at Stiles, at that stupidly perfect mouth that he wants to shove his cock into.
Instead of answering verbally, Stiles just shrugs again and moves forward, mouthing at Derek through the layers covering him. He tugs the zipper down and gets a hand inside, making some kind of pleased noise when he feels how hard Derek’s cock is.
And the whole thing is pure torture for Derek. He whines, bucking his hips forward as he moves a hand to the back of Stiles’ head, fingers tangling in his hair. This is what he’s wanted for a long, long time and while the idea of Stiles giving him head is awesome, he would much rather have the teenager fuck him.
"Fuck me already," Derek mumbles, the words tapering off into a moan when Stiles squeezes his length through the thin layer of cotton covering him. God, he’s never been this hard in his entire life and could probably just come from Stiles’ hand on him right now but then it’s gone, the teen’s fingers hooking into his belt loops.
The denim slides down Derek’s thighs and he steps out of them when instructed. When did he become so submissive to Stiles? He doesn’t know and doesn’t even care because this is happening, finally, and he shudders in anticipation.
Stiles mouths at his cock again, sucking on the head and getting the fabric of his boxer briefs wet. Derek throws his head back on a moan and pushes his hips forward, tightening his hold on Stiles’ hair, not sure if he’s wanting to tug him forward or pull him away.
"Im," the teenager starts, running his tongue along the underside of Derek’s cock, "patient."
The Alpha huffs out a long breath and laughs quietly. When Stiles’ head comes back up, he pulls back and grin at Derek with a glint in his eyes, fingers wrapped around the waistband of his briefs. Then the fabric comes down and it’s moving at a tortuous pace, making Derek squirm and whimper and beg.
Ha. Imagine that — Derek Hale begging.
Finally, after what seems like forever, Derek feels the fabric fall around his ankles and he steps out of it, kicking his underwear away. He blushes a little, standing there naked in front of Stiles, and sucks in a deep breath when the teenager bites just underneath his navel.
"You little — " Derek starts, gasping when he feels Stiles’ mouth around the head of his cock and it feels better than he could have imagined. Those lips are warm and slick and feel so good against him that Derek can’t help but buck his hips forward, whining loudly.
Stiles laughs quietly and flicks his tongue against the slit before pulling back. “Alright, aright,” he mumbles and moves off the bed, pointing to the middle. “Lay down and I’ll get you ready.”
And Derek doesn’t have to be told twice. He moves onto the mattress and sits on his knees for a moment while he contemplates how he should lay down. Does he lay on his stomach or his back? Maybe his side with his leg lifted and Stiles behind him? God, there are too many choices so he just drops down onto his elbows, sticking his ass out.
The bedside table’s drawer squeaks when Stiles pulls it out and Derek shivers. He knows what the teenager is going for, knows that they’re only a few minutes away from having sex, and he moves a hand down to grip his cock, stroking it slowly. Oh, he’s not going to last when Stiles finally fucks him and that’s completely fine with Derek.
"Look at you," Stiles murmurs as he drops the bottle of lube onto the bed, running a hand along Derek’s back, then over his ass. The tip of his middle finger runs over the Alpha’s crack and he presses it against his hole, rubbing around the rim slowly. "All ready for me, huh?"
Derek just whimpers in response.
It’s another minute before Stiles sits on the bed. Derek can hear his boots thudding against the floor somewhere, can hear the sound of his khakis falling down, and he shivers. God, he’s never wanted something - or someone - this badly before in his entire life.
Finally, the bed dips behind him and Derek closes his eyes, sucking his lower lip in between his teeth. The sound of the bottle top opening makes him whimper and he waits what feels like hours for Stiles to press a finger against his hole.
When Stiles touches his hole for the first time, Derek jumps a little. The lube is cold but warming up slowly as the teenager teases him for a moment before pushing inside. It’s a new feeling, something Derek has never experienced with someone else before, and it feels like forever has gone by before Stiles’ finger is pressed in all the way. God damn that kid and his long ass fingers, Derek thinks.
Stiles starts to pump the digit in and out slowly, running his other hand along the back of Derek’s thigh, knuckles brushing along his skin. He shivers almost violently and moans wantonly as he pushes his hips back shamelessly, the sheets twisted around his hands.
"Who knew that you would enjoy being a bottom?" Derek moans at Stiles’ words and gasps when he feels a second finger pressing against his hole. He doesn’t know how big the teenager’s cock is because he’s never seen it but part of him just wants Stiles to shove in without worrying about the prep.
He is a werewolf, after all, so he’ll heal almost immediately.
The thought of telling Stiles to just hurry up and fuck him dies away, though, when the teenager crooks his fingers and finds Derek’s prostate. A howl escapes and he doesn’t even bother to be quiet at this point, not caring if his neighbors complain about the noise. Though the howling will be a little hard to explain when his landlord comes around but… oh well. Derek doesn’t give a fuck.
"Stiles…" Derek whines, pushing his ass back in a silent plea for more. He’s obliged when the teenager slips a third finger in and it’s a tight fight but Derek relaxes, lets Stiles in.
Before long, he’s moaning and panting, begging for Stiles to fuck him. The teen says he needs a little more prep and slides a fourth finger in, which has Derek howling again. There’s pain that comes with four fingers and while it fades almost immediately, the Alpha still whimpers when he feels it.
Stiles slips his fingers in and out slowly, increasing the pace as Derek’s moans become more and more desperate, turning into whines and whimpers and little ‘please’s. He sinks all four back in and spreads them as much as he can before pulling them out slowly, running two fingertips around Derek’s rim just to tease him a little.
"Turn over, I want to look at you."
Derek blows out a long breath and moves shakily, rolling over onto his back. He spreads his legs as wide as he can and pushes himself up onto his elbows, watching Stiles get rid of his boxers. This is another thing he’s been waiting for, to see the teenager completely naked, and he holds his breath in anticipation.
And it all rushes out of his lungs when he sees Stiles’ cock. It’s bigger than any he’s ever seen in real life and it’s the same size as his own — if not bigger — and Derek whimpers. There is no way that is fitting inside of him.
"What’s the matter?" Stiles asks as he pours lube onto his palm and strokes it over his cock slowly, his eyes locked on Derek’s face. Derek, who’s staring straight at the teenager’s cock, his own throbbing in response because it is nice. It’s long and thick, curved up toward Stiles’ stomach when he pulls his hand away… but he’s worried about it not fitting.
When Stiles says his name, Derek looks up. “Huh?”
"I’m… fine." Derek lies easily and shakes his head, letting out a nervous laugh as he watches Stiles move around, grabbing pillows from the top of the bed. The Alpha lifts his hips automatically and shivers when he feels the pillowcase moving along his lower back. The whole time, he can’t keep his eyes off Stiles’ cock and, god, that thing is huge. It’s a fucking monster — and Derek snorts out a laugh, rolling his eyes at the comparison.
Once Derek is up on the pillows and his knees are pushed against his chest, arms hooked around them, Stiles settles into his position. He’s sitting on his knees in front of the Alpha, one hand moving along his flank as the other wraps around the base of his cock. “Relax for me,” he says and presses the head against Derek’s hole.
And Derek is the complete opposite of relaxed. The feeling of just the head pressing inside of him makes him howl and he tries to move away but knows that would only hurt Stiles’ feelings, so he puts his brave face on and endures it.
For a few minutes, anyway. Because when Stiles has two inches inside of him, Derek feels like he’s being split open and he breathes hard, whimpers and wiggles against the teenager, tears welling up in his eyes because it’s too big.
"Ouch," he mumbles when Stiles tries to breach further.
Stiles raises a brow and mumbles, “Does it hurt that much?”
Derek nods his head and hisses, digging his nails into the backs of his thighs.
"Oh my god," the teenager breaths and laughs. "You’re a big bad Alpha werewolf and you can’t handle a scrawny teenager’s cock?”
"It’s too huge, Stiles! You could have warned me.”
"I thought seeing the size of my, uh, package would kind of tip you off.”
Snorting, Derek opens his eyes and looks up at Stiles. “Well,” he grits out, “it didn’t.”
"Clearly." Stiles shakes his head and stays still, moving his hand along the Alpha’s flank one more time, trying to relax him. "I’ve only got three of nine inches in you. The other six will come easier if you just take some deep breaths and calm down."
"Right, calm down." That’s kind of hard to do with a huge dick in your ass, Derek thinks, and shakes his head, though his body does stop shaking when Stiles strokes his thigh. "Try another inch," he says, his voice quiet.
Stiles nods and pushes in slowly, getting maybe half an inch in before Derek shouts. “Oh god, you big fucking baby,” the teenager mutters, laughing.
"How about we trade places, huh?"
"You wanna do that?" Stiles asks, raising a brow. "Do you really want to see a human take your big fucking cock in his ass with no problems? Because I think that’s kind of humiliating and I didn’t know you were into that.”
Derek swallows hard and breathes in shakily. “Fine,” he grumbles and pushes his hips back, wincing at the pain that shoots through him. “Fuck me.”
"Are you going to cry this time?"
"I wasn’t crying.”
"Uh, dude, your face kind of says differently."
"Just fuck me before I change my mind."
Stiles nods and grips the base of his cock again. He slides it in again, a little faster this time, and though there’s a lot of pain that comes with each inch, Derek keeps quiet. Well, for the most part; he does whimper and whine a little but when Stiles’ cock is buried inside of him, he settles down.
They both take a moment to relax before Stiles starts moving again. Pain flares up but Derek ignores it, focusing on the pleasure instead. Even though it hurt and he wasn’t enjoying himself for a few minutes, Derek’s cock is hard and throbbing, with precome smearing across the head.
But things quickly change. Stiles pulls his cock out all the way and attempts to slam back in but Derek yells a litany of curses at the top of his lungs. It hurt so much more going in the second time than the first and, huh, isn’t that funny? Derek thinks it would hurt a lot more the first time and by the second he would be adjusted.
"It’s too fucking big, stop,” he says and Stiles stills, half of his cock buried in the Alpha.
"So what am I supposed to do, then?"
Derek breathes harshly and shakes his head. “Just fuck me with half of it,” he mumbles and turns red when Stiles snorts at his suggestion. “Or you can go without fucking me.”
"Fine, you big baby."
When Stiles starts moving again, Derek actually enjoys the feeling. His hole is stretched around the teenager’s shaft and he winces a little each time Stiles pushes in but it’s not that bad. He even tells the teen to start working up another inch, then another, until he’s got nearly the entire length of his cock in Derek.
The pleasure outweighs the pain and Derek starts moving against Stiles, wrapping both legs around his waist, tugging him closer. A moan escapes the teen’s throat and Derek grins, moving his hands all along Stiles’ chest, thumbs brushing along his nipples.
"Derek," Stiles gasps, his head thrown back and neck exposed. God, Derek wants to lean up and sucks every inch of that pale skin, wants to bite and suck until Stiles’ neck and throat are covered in hickeys.
Instead of doing that, though, Derek moves a hand to the teen’s shoulder and squeezes, fingers digging into his skin. He knows there will be bruises and that’s what he wants, he wants to put a hand print on Stiles to show everyone that he’s taken.
A loud, almost feral growl escapes when he thinks about that and he moves his hips against Stiles’, rotating them slowly and gasping. “Stiles,” he breathes, repeating it over and over as he drops his hand down, wrapping it around his cock.
"Fuck, you’re so tight." The words go straight to Derek’s core and he arches off the bed, feeling himself getting closer and closer. Each time Stiles thrusts in, he angles his hips and hits the Alpha’s prostate a few times, which makes him see stars behind his eyelids.
It takes a few more thrusts for Derek to come and his whole body shudders when his orgasm hits him, ripping through him harder than any other has. He pants and gasps, shooting come all over his hand and torso, head thrown back as he pushes his hips toward Stiles.
As he comes down from his orgasm, Derek opens his eyes to look at Stiles. The teen has his mouth hanging open and his neck, chest, and face are flushed. The sight makes Derek tremble and he starts talking, telling Stiles to fuck him harder, to come inside of him.
"Derek…" Stiles groans his name and drags it out, his head thrown back on a louder moan as he slams his hips forward. Another inch of his cock slides into Derek and he winces, clenching his muscles around the shaft as he listens to Stiles come undone.
A litany of curses comes from the teen’s mouth. Derek’s name and ‘oh god’ are mixed in with them, coming out as broken gasps and quiet moans. It’s seriously one of the best things Derek has ever heard and he knows that he’ll be thinking about it later and jerk off, remembering how perfect Stiles sounded - and looked - when he came.
They breathe harshly together and Stiles pulls out carefully, falling onto the mattress beside Derek with a shaky laugh. He licks his lips and the Alpha watches him for a moment before running his fingers through the come on his own stomach and chest. Stiles’ eyes open just before Derek pushes his fingers between his lips, sucking on them slowly.
"Fuck," Stiles groans. "Don’t do that."
Derek grins and takes the digits out, gathering more come on them before bringing his hand up, to Stiles’ mouth. “Do you want some?”
Without answering, Stiles wraps his lips around Derek’s fingers and sucks them down to the knuckle, sucking obscenely. His cheeks hollow out and if he hadn’t just come, Derek knows that his cock would be hard as fuck from watching that.
After pulling his fingers away, Derek kisses Stiles slowly, licking into his mouth and moaning when he tastes himself on the teenager’s tongue. They kiss languidly for a moment before Stiles pulls back and grins, licking his lips slowly.
"Best birthday ever," he mumbles and Derek nods in agreement.