"I've got a theory," Stiles says.

Derek looks up from his book. The words are swimming in front of his eyes. He's read the same paragraph several times, and it still doesn't make sense.

Stiles lies on his stomach on Derek's bed. There's a book open in front of him, but his chin is in his hands. His legs kick in the air. A strip of pale skin is exposed across his lower back, where his shirt has ridden up. Derek's eyes fix on a single mole, right above the low waistband of Stiles' pants.

Just above that, peeking out from beneath the hem of Stiles' shirt, three red lines mar the skin. Derek swallows and looks back up at Stiles' face.

Stiles grins. "Were you... Were you just checking out my ass?"

"No," Derek says. He's not lying. "Your theory?"

"Right." Stiles closes the book, shoves it away. "There's nothing in these dusty old books." He pushes himself up to his knees, then settles, cross-legged in the center of the bed. "You can have nice things now."

Derek blinks. "Stiles, what the hell—"

"Let me finish." Stiles closes his eyes and breathes, hands loose and relaxed in his lap with his elbows on his knees. When he opens his eyes there's a frown creasing his forehead, like he's trying to find the right words. "You blamed yourself. For Paige's death, for what Kate did to your family. Peter told me that blue eyes meant you'd killed someone, but I don't think that's it. You had all that guilt, and it built up over years. If you'd never met Kate, maybe your eyes would have been gold again when you'd worked through what happened to Paige."

Derek stares. Stiles looks back at him, waiting.

"Then why now?" Derek says.

Stiles shrugs. "You were just a kid when Kate killed your family. You didn't understand that it wasn't your fault. This time, I dunno. The way she manipulated you was fresh in your mind when you grew up this time. You had a better perspective. You could let go of that guilt, you could accept what had happened, and move on."

Derek's heart pounds as Stiles' words start to make a kind of sense. The anger he anchors himself to has been conspicuous in its absence, and it speaks of a kind of acceptance he's never had before.

Stiles looks down at his hands, picks at a fingernail. "You're letting yourself have nice things," he says under his breath.

Derek puts the book down on the coffee table and crosses the room. He sits on the edge of the bed. "Is that where you come in?"

The pale skin over Stiles' cheeks flushes pink as he looks up. "I dunno." He shrugs and averts his eyes again. "Maybe?"

Derek hums as he reaches out, lifting Stiles' chin so he can kiss him. It's soft and chaste, over quickly. "Except my anchor is gone." He slides his hand under the back of Stiles' shirt, feels the raised welts left behind by blunt human fingernails. "If I let myself have nice things, Stiles, I'm liable to break them."

"Dude." Stiles snorts. "I almost came in my pants when you did that. It was hot." He takes Derek's face in his hands, kisses him back, warm, soft lips and just a hint of tongue. "I trust you. And I think you trust me."

It's not like Derek hadn't sensed it at the time, Stiles' arousal flaring as Derek dragged fingernails over his skin. They were kissing, grinding against each other on Stiles' bed just the day before. Stiles' father was downstairs at the time, though, so it went no further. Has never gone any further, in fact, because this is new. So new that every kiss, every touch or word or glance is still fresh and very exciting.

Today is the first time they've been truly alone since the first unexpected, yet frantic kiss a week ago, since Derek gave in to the thoughts he'd had as a teenager, not knowing Stiles at all, not remembering that Stiles was a thing he wasn't supposed to want.

And if Stiles is right, not remembering that he wasn't supposed to allow himself to have the things he wanted.

He traces the scratches again with his fingertips. Stiles shivers in his arms, and Derek starts to pull away. "I could really hurt you," he says.

"You didn't even draw blood," Stiles says. "Your claws weren't even out, dumbass."

"What if they were?"

Stiles' eyes seem to sparkle, and his mouth pulls into a smirk. He grabs his shirt by the hem and yanks it off over his head, flicks it onto the floor. There's a hint of his arousal in the air. "I trust you." He lies flat on his stomach, and reaches around to touch the red lines low on his back. "Start by kissing that better."

"You're insane," Derek says, as he stares down at the pale expanse of exposed skin.

"Nah," Stiles says, kicking his legs up again. "Don't be a baby, Derek. Kiss it better."

Stiles' heartbeat is a little quick, but steady. With the scent of his arousal in the air, it's just excitement. He's not afraid, or even nervous. The slight sharpness to his scent is anticipation, nothing more.

So Derek leans down, drags his palm down Stiles' back as he presses dry lips to the marks.

Stiles hums and wriggles. "S'nice. More."

Derek pulls his legs up onto the bed, crawls up and over Stiles on his hands and knees. His chest brushes over the swell of Stiles' ass as he bends his head to lick over grazes that are invisible to the eye, but very evident to his sensitive tongue.

Stiles' breath goes shaky, and he shifts his hips. His arousal spikes, the scent hitting Derek like a wall.

His head spins. He forces himself up, away from the source of the scent, shifts so his knees rest either side of Stiles' hips and he breathes against the back of Stiles' neck.

Stiles whines and pillows his head on his arms. Head turned sideways, Derek can see that he's pouting and flushed.

"Shh." Derek kisses the back of Stiles' neck, follows each knob of his spine down, then rests his forehead between Stiles' shoulders. "Don't move."

Stiles' hips grind into the mattress again and he whimpers. "Sure," he says, voice high-pitched and almost frantic. If his arousal wasn't almost completely obscuring Derek's ability to think, Derek might assume it was panic.

It's not.

Derek wraps his hand around Stiles' waist. Light enough to not leave a lasting mark, he drags his fingernails around to Stiles' back, and then holds on as Stiles moans and writhes underneath him.

"Holy shit, Derek," Stiles gasps.

Derek lifts his head, just in time to see white lines fade to pink. "How does that feel?"

"Stings." Stiles takes a few breaths. "Just tingles now. I can still feel it." He looks up, lifts his head a little as he strains his eyes. "Kiss it better."

Derek backs up and licks over the lines. Stiles squirms beneath him as if it tickles.

"Claws," Stiles says, and then when Derek hesitates, "please."

It takes some concentration to let them out slow. He keeps his hand flat on the mattress beside Stiles' elbow, watches as Stiles' eyes go wide and his breath hitches. "Don't move," Derek repeats, and then he pulls himself up on his knees, keeps them locked around Stiles' thighs to keep him still.

He drags his claws slowly the length of Stiles' back, from shoulder to the swell of his ass, leaves behind five perfect lines of blanched flesh, watches as they turn pink.

Stiles moans the whole time, and as soon as Derek pulls his hand away, moves his hips against the mattress. He reaches back with one hand. "I can't— I can't even feel it, I mean, I can feel it, still feels like it's there but I can't—" He strokes his hand back and forth over the lines, then gives up and shoves his hand beneath him, rocks his hips and grunts.

"Don't," Derek says. He's hard enough himself that it hurts, cock straining against the fly of his jeans, but he ignores it. "Don't make yourself come."

Stiles whimpers and tries to turn over. Derek holds him down with one hand. "I have to kiss it better," he whispers, and then starts to trail open mouthed kisses all the way down the lines.

"You," Stiles pants. "You evil bastard."

Derek hums and tugs at the top of Stiles' pants, claws scratching into the skin as he draws down the waistband and licks at scored skin.

"Talking about control," Stiles rasps. "I'll give you fucking control—" He groans and thrusts into the bed. "I need to come."

Derek moves back a little more, pulls Stiles' hips away from the mattress, just enough to get his pants undone, and he pulls them, along with Stiles' briefs, down to his thighs, before pushing him back down again.

"Oh my god," Stiles growls in something like disbelief. "You can't do that and not touch my dick, please, Derek, touch my dick."

Every time Stiles says 'please', Derek's cock gets harder and something twists in his belly. He gazes down at Stiles' bare ass, perfect pale skin in contrast to the pink lines on his back. "I'm going to mark your ass," he whispers. "I want to mark your ass, Stiles. And then kiss it all better."

Stiles stops breathing altogether, then sucks in air as he shudders. "I— I'm gonna come."

Derek hushes him, breathes against the small of Stiles' back until his heartbeat steadies and his breathing evens out. "You're okay," he says, over and over. "You can wait."

"You better hurry up," Stiles says, huffing out a laugh. "Oh my god, Derek."

Derek sits back a little, thinking about how best to mark Stiles' perfect skin. Then he lays his hand over one cheek and draws his claws down, just an inch.

Stiles whimpers as he licks over each stripe, starting at the hip, shakes harder the closer Derek gets to the center.

"Fuck," Stiles says as Derek licks into the crease.

Derek puts his hand on Stiles' other cheek, drags his claws from the side this time, and then one by one, slides his tongue down the line and into the center.

"No more claws," Derek says as he pulls them back. Stiles' back and ass are marked enough. The lines will fade, probably by the morning, leaving only the ones from yesterday. Now, he wants to hear Stiles beg again. He moves further down, drags Stiles' pants off completely, then kneels between his spread legs.

Stiles' heart races, his breath rasps as he sucks in air. "Oh, god," he chokes, as Derek drags his thumbs down the crease of his ass to expose his hole. "I'm really gonna—"

Derek drags his tongue over Stiles' hole. "Not yet." He dips back in, licks at the smooth skin around the pucker as Stiles pushes back.

Derek holds Stiles to the mattress by the hips. Choked off words come out of him, pleas for more, and to stop, and to let him come already. They meld into one, long, drawn out groan as Derek works his tongue inside.

Derek can smell it, feel it, hear it in Stiles' voice, just before it happens. When the tiny thrusts Stiles makes against the mattress give him just enough stimulation to get him off. Derek fucks his tongue into Stiles, hard and fast until the boy peaks, writhing and thrashing and crying out as though he's in pain.

Derek kisses the scratches he left on Stiles' ass as he shudders through the aftershocks, and then he crawls up, rolls Stiles onto his back.

Stiles throws his arm over his face. "Your fault," he says, voice hoarse from moaning.

Derek hums in agreement and drags his tongue the length of Stiles' softening cock. His come is a bitterness that slicks down the back of his throat, but he cleans the mess smeared on Stiles' stomach, coating himself in Stiles' scent from the inside.

Stiles shudders and squirms beneath him, then twists his hand into the back of Derek's shirt and tugs. Derek lets himself be pulled up, pushed down beside Stiles' side.

"I'm naked," Stiles whispers. His eyes are glassy and his pupils are dilated. "You're not." He shoves up Derek's shirt, then gives up and goes for his belt. "Need to touch you," he slurs. "This isn't fair. The first time we get naked together and you're all clothed and shit. What's up with that?"

Derek grins and pushes Stiles' hand away. He sits up, pulls his shirt off, then takes off his belt, but he leaves his jeans buttoned, despite his cock straining against the fabric. "It's okay," he says, then strokes down the side of Stiles' face with his fingertips. "Just want to look at you."

Stiles gapes at him. He's soft now, sleepy and pliable. Skin flushed pink and warm. Derek can't help but kiss his open mouth, to lick inside as Stiles moans and runs his hands over Derek's exposed skin. He pulls back to look some more, wonders why he never thought to kiss Stiles before Kate came back from the dead.

"I think you're right," he says. "About my eyes." A little of something else slips away now that he knows. He doesn't care about the money, never did. He doesn't care where Kate is, as long as she stays well away from this. "Stiles," he whispers, and then kisses him again.

Derek loves how Stiles kisses. All in, like it's new, like he can't get enough. He shouldn't enjoy the fact that Stiles is so much younger, that he's the first to touch Stiles like he has, but he can't help it. His heart expands when he realizes he's the first to know what Stiles sounds like when he comes, what he smells like, what he looks like.

He gives in to this feeling of possession, of mine, wrapping his hand around Stiles' throat. His fingertips ache, and he lets his claws out, slow.

Stiles shivers as they scrape over his skin. "Getting hard again," he warns. "Get your pants off, now."

Derek chuckles, low in his chest. With one hand he undoes his jeans, while the other trails lines down over Stiles' chest.

"You can do it harder," Stiles says. His voice is casual, like it's nothing, but his heartbeat spikes. "I don't mind. They'll heal."

The part of him that insists Stiles belongs to him wants it, but Derek isn't an animal. "It'll scar," he says.

The marks on Stiles' chest fade to pink as Derek sits up to wriggle out of his jeans. His cock slaps his belly, sticky at the tip. Stiles' hand wraps around it almost immediately, long, strong fingers that almost don't belong on a seventeen year old boy, and trick Derek's mind when Stiles stares down and says, "I want you to fuck me."

"I'm serious," Stiles says, when Derek says nothing. "You just had your tongue up my ass." He sighs, and strokes Derek's cock. "I want this."

Derek wants it more than he can bear. Stiles, tight and warm around him. But their first kiss was a week ago, and beyond a few desperate, hurried kisses, he doesn't know for sure what it means.

"I want you," Derek says, arching into Stiles' fist. Claws prick the skin of Stiles' shoulders, dig in maybe a little too deep.

Stiles moans and shifts, spreads his legs around Derek's hips. "Yeah, come on."

Derek pulls away as something clicks in his mind. He's so used to denying himself, not deserving anything this good, and he's still resisting. But he smiles as he searches the drawer beside his bed. "I trust you," he says, under his breath. It doesn't matter if Stiles hears, Derek thinks Stiles already knows.

There's lube in his hand when Stiles wraps his arms around him from behind. There are lips and tongue on his throat, hands on his chest, then fingernails scratching at him. Derek shivers, accepting that perhaps unintentional claiming, then, when Stiles bites down on the back of his neck, he moans.

He twists out of Stiles' grip, gums aching as his fangs beg to drop. He holds it in, pushes Stiles down onto his back, lifts him under the knees. The boy goes easy, relaxed, lets Derek fold him almost in half and just look.

He aches to get his tongue in there again. Settles for a finger, pushes it in to the first knuckle and listens to Stiles pant.

A flush spreads up the back of Stiles' smooth thighs when he gets two fingers inside him. He wants to mark them, to drag his claws down each of them, but he's going to wait until he's buried inside.

His gums still ache, his fingertips ache, but he feels more in control now than ever. He focuses on the sound of Stiles' voice, his gasps and half-words as he begs for more.

Derek pushes another finger deep into Stiles' body. Grazes over the boy's prostate. Holds him as he jerks and lets out mindless vocalizations. "Need to get inside you," Derek murmurs. "Need to fuck you."

Pupils dilated, lips wet and cheeks pink, Stiles reaches for him. He's a mess, wrecked and desperate. His cock leaks a puddle of precome onto his stomach, his balls are tight. Derek slides his fingers out, lines up his cock.

He leans over and kisses Stiles' slack mouth as he pushes inside, swallows Stiles' strangled moan.

He shifts, buried deep inside Stiles, feels his fangs come down, his claws come out. He tastes copper, and Stiles hisses, but doesn't jerk away or cry out. He clings even tighter to Derek's shoulders, arches up to meet his hips, licks around sharp fangs without fear.

Derek holds Stiles' hips, allows his claws to prick into Stiles' flesh, not quite enough to draw blood, and he holds on as Stiles writhes on his cock, fucks down on it as he twists, sinuous and abandoned.

He could mark Stiles like this, drag his claws through the boy's flesh and claim him forever as his own. He allows himself this thought, and then he lets it go, wraps an arm around Stiles' thighs to hold them to his chest, and he starts to thrust, long, slow, deep.

He thinks about the bite on the back of his neck, thinks about belonging to Stiles as much as he needs Stiles to belong to him. Thinks about being on his hands and knees, Stiles' teeth holding on while he fucks him hard.

Derek's hips stutter as lightning flashes up his spine. He digs claws into Stiles' thigh, finally marring that perfect, pale flesh. The faint scent of blood fills the air, and Stiles cries out, his body clamping down on Derek's cock as he starts to come.

His cock is still spurting when Derek lets go, electricity sparking all the way to his fingertips. He growls against Stiles' throat, open-mouthed, fangs barely grazing the flesh. His hips jerk with each spasm, filling Stiles deeper and deeper with a scent that'll linger and leave no question.

They belong to each other.

The marks on Stiles' thigh are going to scar. Derek licks them clean, but fine white lines will be there forever. Something twists inside him, knowing it. He nuzzles into the hand in his hair and feels content for the first time in years, perhaps ever.

"You didn't break me," Stiles says.

Derek smiles and lifts his head. "You should cover the others," he says. "They'll fade." He drops a slow, wet kiss to each of the five cuts on Stiles' thigh in turn. "These won't, but you don't have to hide them."

"I won't." Stiles cups Derek's cheek with his hand, strokes under Derek's eye with his thumb. "Gold suits you," he says.

fin