When Stiles feels the bat crash against the back of his head, he's too slow to turn around to face his attacker, before he collapses to the ground. He's conscious enough to feel himself being lifted up and carried, but he slips into darkness before he can open his eyes.
When he comes to, the first thing he smells is dampness, followed by something musky, like something's been burnt. He tries to sit up, but his wrists are strapped to a bed. His ankles too, and there's not enough strength in him to do much more than feebly tug at his bindings. He struggles to keep his eyes open, yet succumbs again to darkness.

When he wakes up again he's naked and face down with someone's fingers in his ass.
It doesn't hurt but it's alien, and Stiles tries to move yelling out, hearing chains rattle as he does so. He doesn't get far, trying to crawl away across the huge white bed he's on. It's a different bed this time, a different room. A bedroom. There's an alarm clock on an upside down crate which doubles as a bed-side table.
"Shh," a voice says behind him, and one heavy hand presses against Stiles's shoulder, stilling him. Whoever it is is big, stronger than Stiles. His head still hurts, his eyes feel heavy, and even though he knows how to throw a punch, he's not sure he'd be able to fight this guy on his best day.
"This'll be easier if you relax," the voice says, fingers pressing into him again.
"Who are you?" Stiles gets out. The words are thick in his mouth. He tries to turn his head to look but the hand's still keeping him in place. "What the hell are you doing?"
"My name's Derek and I'm getting you ready. It'll be ok Stiles. I was in your position once. Trust me, just relax and this'll be much easier."
"Are you gonna fuck me?" Stiles asks, keeping his voice as flat and emotionless as he can yet he hears his voice shake.
"No, not today," is the answer.
Another finger is added and Stiles breathes hard through his nose trying to blink back tears.
"Are you going to kill me?"
The fingers stop their slow, steady fucking and there's a sound of dismay like this Derek guy is offended that Stiles asked. "No" the guy says, and Stiles believes him. "Never. You're far too valuable to us." The hand on his shoulder moves to Stiles's neck and rubs there in a show of comfort. It shouldn't feel nice but it does, which is frightening on a whole new level.
"Peter and I are gonna take good care of you, I promise," says Derek.
The fingers slide out of Stiles, and something else is nudged into him - a brief stretch before his body closes around it, and he realises with a shudder that it must be a butt plug. A weight lifts off of the bed and then there's a squeeze on Stiles's shoulder. He turns his head to see a tall dark haired man with light eyes who looks too kind to be involved in this, too wholesome.
"I'll see you soon. Don't worry, you're going to be fine". Derek says before departing.

Stiles is chained in a way that he can't turn over or move much - perhaps six inches in any direction, shuffling across the bed. Any movement makes the plug shift inside him. He considers trying to push it out, though it felt pretty big when it was going in. He tests the strength of the chains, tries to wriggle his hands out of their cuffs, but none of it's any use. He watches the alarm clock count down eleven minutes before a door opens and there's a new presence in the room.
"Stiles ," says a new voice, sounding pleased and… proud.
"Who are you?"
""My name's Peter. Peter Hale. You met my nephew a few minutes ago." comes the reply. There's the sound of fabric moving, the sounds of someone getting undressed, but it's not until Stiles hears the sound of a zipper being undone that he really tenses up. This is happening.
"You should relax, Stiles," Peter says. "I don't want to hurt you."
"Fuck you," he spits. The mattress dips as the man kneels on it, and Stiles is halfway through another 'Fuck you' when there's a sharp, stinging slap to his ass which cuts it off.
"I said," Peter says, steel in his voice, "I don't want to hurt you. But you're going to have to cooperate."
A hand pushes against the middle of Stiles's back - not with the same kind of strength behind it as Derek, but enough to stop Stiles from squirming too much. His head is still throbbing, not a huge amount but enough to make his head a bit fuzzy and his reactions slow. He can't shake off the feeling that he could do something if he could work out what, but he can't, can't do anything. Everything's just out of reach.
The man moves Stiles's knees, pushing his thighs up and apart before the plug is tugged out of him. It's slick enough that it goes easily, but it's replaced with a sense of emptiness, a new discomfort.
The man's weight shifts and then there are two knees pushing beneath Stiles's thighs keeping his legs open before two thumbs pull his cheeks apart. "Just as pretty as I thought you'd be," Peter says, and that's all the warning Stiles has before there's the wet slipperiness of a lubed cock rubbing along the crease of his ass and catching on his rim.
"Please," Stiles finds himself saying, and he hates himself for begging so easily. "Please no."
"Shh," Peter says, running a hand down Stiles's thigh as if to soothe him. The sick part is, it does. For all the violence and pain he'd been expecting, this is almost nice.

"So open for me," Peter murmurs, as if he's surprised at it, like Stiles wasn't being prepared for this whilst he was still fucking passed out. As if he has a choice in any of this. He wants to say that, point that out but he can't. He's fixed on the drag of hot flesh over his wet ass, the way it keeps almost pressing in but never quite does. As if the man wants to stretch this out, take his time before claiming his ownership of him.
"Thought about this for so long," Peter tells him. "Pinning you down and fucking you into submission. Could tell you needed this even from afar. So lost so alone," he runs a hand up Stiles's side, leaving goosebumps in its wake. "I could see how desperate you were for someone to look after you, take care of you."
Stiles closes his eyes and pulls on the chains around his wrists.
"I was impressed," Peter says, still rubbing his dick up and down like he's mesmerised by it. "I've been watching you for a while now, watching as your dad leaves you alone night after night to go to work, how your so called best friend cancels on you over and over again for a girl he has no chance with"

Peter lets out a long soft moan as he finally presses into Stiles, violating him in the most intimate way. Stiles presses his face into the mattress beneath him. "Oh yes. This was worth all the watching, baby." He bottoms out, skin pressing against the back of Stiles's thighs. Stiles expects him to hold his hips and pull out again, or start fucking him hard right away, but instead he just stays there, dick as deep as it'll go inside him and hands everywhere, gently sweeping up Stiles's back, over his shoulders, down his arms to the cuffs and back again.
"Isn't this better?" he asks. "Isn't it nicer this way? I'm going to take such good care of you, Stiles."
Stiles's back warms when Peter drapes himself over his body; a weight he has no hope of throwing off. Peter puts his arms underneath Stiles's shoulders in a makeshift embrace and presses down over him, around and inside him.
It's only then, when Stiles is completely covered by him that he starts to move his hips in a slow roll. It feels deeper when he presses back against him, and the rumble in Peter's chest feels loud against his ear. "Does that feel good, sweetheart?" Peter asks, and it's so earnest the way he says it, like this isn't awful, like this is meant to be good
"Fuck you," Stiles sobs. The bed is wet beneath him where he can't stop drooling, where his eyes keep watering. "My dad will ruin you when I tell him about this, you fucker"
"Peter's voice is soft and sweet, shushing Stiles and cooing, "Don't be like that Stiles. Your dad won't have a chance to ruin me, because he's never going to know." Stiles freezes at this comment, whilst Peter still gently moves within him.
Peter goes slowly for what feels like forever, until he begins to pick up the pace and fuck into Stiles a little harder. It's better this way, Stiles reasons, since it doesn't feel so intimate; not some sick approximation of lovemaking. This way it's easier to hate Peter no matter how proud and pleased he says he is with Stiles, he doesn't even know the guy.
"You like that?" Peter asks, and Stiles can tell from his voice that he's smiling. "Knew you would. Could tell how well built you were for this, Stiles. I knew from the first moment I set my eyes on you that you were made for getting fucked."
One of the hands around his shoulders moves down to cup Stiles's dick, wrapping around when Peter finds it hard. Stiles tells himself he's not enjoying this, he isn't, he can't, it's not his fault his body wants this.
"Hard for it, you poor thing," Peter says, letting go of Stiles for a moment before his hand comes back wet and slick. His next thrusts pushes Stiles into his waiting hand, and he bites his lip to stop himself from crying out.

"When was the last time you had someone look after you, hmm? When was the last time someone gave you what you need?"
"Stiles can feel an orgasm building, and he hates himself for it. There's a burning shame crawling over his skin and he knows he's flushed red down his back, his face, his neck. He's had one or two guys comment on the way he blushes, telling him it adds to his youthful look, but he's never been embarrassed about it before. This shouldn't be turning him on and he hates himself for it. He hates Peter and doesn't understand why this is happening but most of all he hates himself for the way his orgasm is an inevitability, another part of him that's out of his control.
"Let go, baby boy," Peter whispers against his ear. "You want this, don't deny yourself."
"No," Stiles grits out. "Please. Please stop."
Peter shushes him again, and the chains rattle as he starts thrusting even harder, pushing Stiles into his fist until Stiles is desperately trying to force himself not to come. "Let it go, baby," Peter orders, and he moves his head so his nose brushes against Stiles's ear when he stills his movements. He stops, buried inside of Stiles, moving to press soft kisses along the line of his neck. "Let it go," he whispers.
It undoes Stiles, these soft, sweet kisses that turn into sucking bites that'll leave marks, marks to prove how owned he is, how much he doesn't belong to himself anymore. He fights it but that's what makes him come in the end: Peter's hand wrapped around him and his lips on his neck, pulling an orgasm out of him as his hips move in tiny, slow circles, like he's teasing it out of Stiles, trying to make it good Stiles comes so hard he feels like he's going to black out, and he's sure he almost does when Peter starts moving again, even after he's made Stiles slicker with his own shuddering orgasm.

"All mine now," Peter says, breathless. He's still buried inside Stiles, still pressing him down. "Never going to let you go.