It's just past 3 AM when Stiles' window slides open, letting in the syrupy summer air and the sharp smell of cut grass.
Derek heaves himself over the edge of the window, eyes flashing when he realizes Stiles is still awake.
He's spread out on his back, limbs akimbo, and a small white fan clipped to his bedframe circulating hot air and white noise. He turns his head towards his alarm clock and then back towards Derek, struggling to focus in the darkness of his room. "You were supposed to be here hours ago, y'know, when my dad wasn't here? He just got back from work, he'll be going to bed soon".
Derek shrugs. "I was busy", he replies as he points to the tear in his shirt that frames a section of tanned, freshly healed skin.
Stiles sits up on the edge of his bed, skin flushing as Derek walks towards him and runs a hand down his face, thumb stopping on his bottom lip. There's a sort of heated purpose in the way Derek gazes at him, and he can't help but to run his tongue across the finger slowly working it's way into his mouth. Derek steps back, shedding his shoes and socks and Stiles moves back to let him into bed, but he pads away towards the bedroom door. Shortly after, Stiles hears the noise of the water turning on in the bathroom adjacent to his room. He rolls over, finds the lube, gets to work and waits.
Stiles is dozing off again when Derek gets back. His pale skin is flushed from the heat, and his sweats are low on his hips, hastily pulled up. He cracks one honey colored eye at the door when it opens, and flips the thin sheet back from the side of the bed so Derek can slide in closest to the wall. He jumps when Derek's hands settle low on his hips, pulling him back towards the hard line of heat coming from from Derek's cock as it presses against him. Suddenly the sweat working it's way down almost every inch of his body grows cold, and he arches his back to lean his head back on Derek's shoulder and press a sloppy kiss to his mouth, sucking and nibbling on Derek's bottom lip as he works his sweats down.
Derek rolls them, hovering over Stiles, and sending the fan crashing onto the ground. Stiles scrambles to reclip it to his headboard before the noise gets his dad's attention, but judging from the creaking slowly working it's way towards his door, it's too late. The door doesn't open, but his dad knocks softly, calling out his name.
"Stiles? Everything okay in there?"
"Yeah, everything is fine, I just kicked over my fan.", Stiles replies, fruitlessly swatting Derek's wandering hands away from his thighs. Derek spreads one large, warm hand across his ass, pressing in and searching towards his prostate. Derek's other hand is slowly but surely working his half hard cock until it swells, bouncing towards his bellybutton as Derek lets him go to reach for more lube. Once he finds what he's looking for, he presses an open mouthed kiss to Stiles' collarbone and works his away down Stiles' chest, biting and kissing as he goes. He runs his hands up and down Stiles' thighs, pressing kisses to the crease where his thigh meets his groin.
Stiles presses the meat of his thumb into his mouth and tries not to moan too loudly as his father walks away from his door. But instead of heading back to his room, his foot steps fade downstairs and into the living room right under Stiles' bedroom.
His father jokes all the time that being in the living room is like being in Stiles' bedroom with him, just because of how thin the floors are. Stiles swallows a gasp when Derek sucks tenderly at the head of his cock, slurping up precome and then slowly working his way down, meeting Stiles' glance with supernaturally blue eyes as he does so. He works his other hand back under Stiles, tapping at his thigh so he'll spread his legs wider and lie flat on his back. Derek presses the flat, smooth surface of his wide tongue against the throbbing vein of Stiles' cock and then presses his wide fingers back into Stiles, working his fingers and spreading them, before searching up, until Stiles is grinding up into the wet, velvet heat of his mouth, trying not to bite through the side of his arm to keep quiet.
He's leaving trails of shiny spit across his arm as he bites down trying to keep quiet, but it's like Derek is doing everything he can to wrench even the tiniest of noises out of him. He sits up again, stomach straining and jumping at the sharp knot of pleasure settling in his groin.
"You do realize that if it gets too loud in here, with some of the activities that are-ah, happening currently, that not only will my dad be able to hear us, but he'll, fuck, probably open the door and see? I don't actually want this relationship to end in your, shit, death, contrary to-hng- popular belief.", Stiles chokes out, hips jumping up when Derek presses down, lips meeting the base of Stile's cock. His eyes are watering and his throat is working around the head of Stiles' sensitive cock.
Derek pulls off his cock with a loud slurp, and pulls his fingers out of Stiles altogether, before hitching Stiles' legs up and pressing the head of his cock in with a shaking hand to steady himself. He leans over, and presses a kiss to Stiles' swollen lips, and then to his neck and his collarbone.
"I guess you'll just have to stay quiet", he grunts, pushing in slowly until their bodies meet. He braces his left forearm on the side of Stiles' head and puts one hand on Stiles' left hip and pulls back until just the tip of his cock is in Stiles, and then he thrusts forward, over and over again as Stiles slides up his cheap cotton sheets with the movement. Stiles goes quiet and a little cross-eyed when Derek thrusts in deep, and slows down to a deep, dirty grind, hips rolling and rubbing his cock right across Stiles' prostate.
His face goes slack with pleasure as Derek leans down and buries his head in the crook of Stiles' neck, snuffling his own moans into the damp skin there.
Stiles arches his back, coming up to meet Derek's thrusts as he comes. His full body shudders and he bites down on the first patch of skin he can sink his teeth into to muffle the yell he lets out as Derek wraps a hand around his sensitive cock, pumping out the final bursts of come onto his stomach and as far as the bottom of his chest. His body shudders and shakes as he comes down from his orgasm. Derek is still thrusting into him, and his cock gives a feeble twitch.
His nerves are pulled taut and ready to snap, as he feels Derek's arms come up and wrap around him. Now the little self control that was helping him hold back his noises is gone, and all he can feel is the sensation of Derek's cock filling him up. He can't really hear himself through the haze of pleasure that comes over him, but he knows that whatever it is is too loud. He's mumbling curse words into the side of Derek's neck, through the hot breaths and moans that are being pushed out of him. He's trying his hardest to stay quiet still, but it's almost like Derek is doing it intentionally.
The louder he gets, the faster and the deeper Derek fucks into him, and he can feel the sharp pinprick of Derek's claws against his skin. He can feel tears gathering in the corner of his eyes from the overwhelming sensation of pleasure rushing through his body as Derek lines up his cock and thrusts into him over and over again, slowly and tortuously. If they were alone, he'd be yelling loud enough for the neighbors to hear, and holding that back is killing him. He can hear his dad moving around downstairs, getting ready for bed, and turning on the alarm.
Derek hears footsteps heading towards the stairs which only makes him move faster, trying to make the scream stuck in Stiles' throat come out. The sounds of Stiles' harsh breathing only makes the silence in the house stand out more. To the sheriff, there are only two people in his house, himself and his sleeping son.
Derek pauses, as he hears the floor creak in the patch of wooden floor right by Stiles' bedroom floor. Stiles whines, but Derek puts a hand over his mouth as he hears the shower start running in the bathroom across the hall. He sits back on his haunches, pulling Stiles into his lap. His hips are still flush with Stiles' but he's still, only grinding his hips slowly, just to see the flush spread down Stiles' neck and chest. His entire body is going pink with the effort of holding back the noises he so desperately wants to let out. His breath catches and he hiccups a little with a quiet sob as Derek starts moving again, thrusting up into him.
Stiles collapses forward onto him, and there's a hot, damp patch on Derek's shoulder from his mouth that is open in a choked, low moan. He's letting out a little "ah, ah, ah", and it's getting louder and louder with each thrust. Derek knows he has a grin worthy of the Cheshire Cat on his face, and the louder Stiles gets, the harder his cock gets as he fucks him into another orgasm. This time Stiles scrapes his blunt nails across Derek's back and shoulders as his body seizes up and his toes curl and cramp. He can't help the slight yell he lets out as Derek comes with a growl shortly after him, pulsing, hot and wet inside of him. They both collapse back onto the bed with a dull thump as Derek pulls out slowly. Stiles wants to move his leg but his entire bottom half is still numb with pleasure and he can't catch his breath enough to wipe away at the come dripping down the back of his thighs.
Derek pulls him close and rearranges the fan so it's facing closer to the bed and as it blows over them, the sheen of sweat on their skin dries and Stiles shivers. Derek is nuzzling into Stiles' neck, reveling in their combined scents as he rolls them onto their sides.
"Just so you know, I'm getting you back for this. I know exactly what you were trying to do", he says, grinning weakly when he feels Derek freeze behind him.
"I wasn't trying to do anything but make you happy", Derek replies.
"You were trying to get us caught, you sick bastard. Just for that I'm getting bars on my window", Stiles says rolling onto his side so he can glare at Derek over his shoulder, but it doesn't last long when Derek captures his mouth in a kiss.
"I'd just tear them off", Derek says, pulling away with a smile.
"Then I'll cover them in spikes, asshole." Stiles yawns around the edge of his sentence and burrows into his pillow as Derek pulls him close.