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It's so fucked up.
That's what he's been thinking, and occasionally saying, since waking up with Sam tucked next to him, naked and thirteen again. Even now, after freaking out and letting Sam freak out and establishing that it's still Sam, just like he was when they passed out in a fucked-out heap the night before -- it's fucked up.
"Oh, God," he breathes. "That's it, baby, open up for me."
Sam gives him a little moan, twisting on the two fingers he's taking. Dean can feel his little hole stretch and pull around them, all slick and wet and tight.
"Dean," he mumbles, rubbing his flushed face against his collarbone. He spreads his legs a little more, stretching one along Dean's. It's not even long enough to meet his foot; Sam's skinny little toes flex against his calf as he huffs, "You're so big, Dean."
It's true, but God, it shouldn't be that hot. His cock lets out a little blurt of precome against Sam's tummy as he fucks his fingers back and forth. He can feel Sam's there against his hip, a small, hard bump.
"I wanna feel your cock in me, Dean," Sam mewls. Dean twists his fingers, pulling 'em out and then sticking just one back in, sliding nice and deep.
"You're so little, Sammy," he whispers, not totally sure if he's trying to appeal to the Sam that's in there or if he's lost in this fantasy. Either way, it's true: this skinny little boy in his arms is tiny, triggering every barely-smothered big brother instinct he's got. He wants to hold him close and protect him from the world, but Jesus Christ, he also wants to fuck him good and deep. "Can you take it?"
"Yeah!" Sam reaches back, grabbing at his hand. It's scrawny against his, spindly fingers scrabbling against his thick, lube-slick ones. "Gimme another one, I can take it--"
Dean lets out a long, slow breath as he pushes that second finger back in the tight ring of his hole, and then adds a third, slowly stretching him.
Sam's eyebrows knit in concentration, a look so familiar that Dean suddenly lets go, gives over to this thing. It's still his Sam, even if he's in this pipsqueak body.
"Yeah," he breathes. "You can take that, can't you? Just open up that hole for me, kiddo, like a big boy."
Sam thunks his forehead against Dean's chest, moaning way too hard for his little voice to handle. He nods, baby-fine hair wisping against Dean's skin, and presses back against his hand.
"I can take it," he repeats, voice cracking a little. "Give it to me, Dean, give it -- oh, Dean!"
He lifts his head up then, staring down at him all wild-eyed and flushed. He looks totally fucking depraved, a little thirteen-year-old slut, and Dean turns his fingers, pressing deep to find that spot.
"Does that feel good, Sammy?" he growls, leaning up to nip at his smooth little chin.
"Yeah -- Dean, aw, fuck." He rolls his hips, fucking himself back on those fingers, the head of his skinny little cock dragging against Dean's stomach. "Right there, God. I wanna you -- want you to touch it with your cock."
That's it, that's all he can take; Dean pulls his fingers out with a dirty, wet pop, and grips his narrow little hips.
"You're gonna ride my cock, Sammy." He barely recognizes his own voice, it's gone so gravelly and harsh. "You're gonna ride it for me and take it all, okay?"
Sam's little cheeks are burning red, but his eyes are all lit up like Dean just promised to take him to an arcade or something.
"Yeah," he groans, shifting from knee to knee impatiently. "Yeah, God, Dean, please--"
It's so fucking easy to just move him like this. Dean's hands span the whole width of his tiny hips, and it's nothing to grip 'em good and tight and guide Sam right down, till that freshly popped little hole is nudging the head of his cock. He's not sure at first if Sam is actually going to be able to do it, but they both push, nice and easy, until the head slides in.
"That's it," he sighs, eyes falling shut. Sam's hole pulls in reflexively, tightening around the neck of his cock before he wills it loose again. "Come on, baby, you can take the rest."
It's a slow slide down, but he does. He takes the whole fucking thing, until he's sitting there on Dean's hips, cock bobbing in front of him.
"I did it," he breathes, looking down at him with a wide, cheeky grin that Dean hasn't seen in over a decade. "I took your whole cock, Dean."
"Yeah, you did." His heart is pounding against his chest, and he knows he's gonna blow before he wants to. There's just no two ways about it, with Sam looking like that, talking like that, like getting split in two by Dean's thirty-year-old cock is the greatest acheivement of his life. "Good job, baby boy. Now ride it for me."
"So bossy," Sam mutters, but he's still grinning at him when he presses his palms to Dean's chest and rocks on it, tiny little hole tugging all the way up the length and then back down again. He's panting by the time they connect again, Dean's balls pressing up against his ass, and tips his head back as he flexes around him.
Dean stares, taking it all in: his skinny, heaving chest; his pink pebbled little nipples; the way his tummy pulls in all tensely under his obvious ribcage when he sucks in a big breath. It's unbelievable how young he is right now, how smooth and pale his skin looks up against Dean's hairy legs and muscled arms.
"You're not gonna break me," Sam huffs when Dean slides his hands up his back, but oh, he's pretty sure he is. Sam's fragile, tiny, his little baby brother again. And he's bouncing on Dean's cock.
"Does that feel good?" he prompts when Sam comes down on another stroke.
"Yeah," he manages, voice sounding dangerously wobbly. "God, Dean, you're so big. 'S like you're filling me up. I can feel you everywhere."
His fingers dig into Sam's hips, holding him there as he rocks upwards and makes sure he really is full, taking every last inch Dean can give him. He doesn't even know how he's doing it -- it feels like he's gotta be taking up his whole fucking abdomen, he's in there so far, but Sam just gasps and grips his shoulders, insides going tight around him for a second.
"So deep, fuck," he pants down at him.
He wriggles a little, sliding his hips back and forth like he's trying to feel him even more, and that's just it -- Dean rolls them both over until he's got Sam pressed down in the bed, legs spread around him.
"You want it deep, huh, Sammy?" He props his hands on the mattress, giving him a nice, slow thrust. "Deep like that?"
"Oh God, Dean," Sam huffs, one skinny, lanky leg winding around his waist. "Yeah, like -- that!"
It's different than fucking a chick, but that's what comes to mind -- driving in nice and hard, taking what he wants. Sam's little stiffy just bounces there between them, hitting against his stomach every time he slides home, and his whole little body kinks up when Dean gets a hand around it.
"God, baby, yeah. Give it up for me."
"Feels so good, Dean." Sam's little curls are sticking to his forehead, he's sweating so hard, one hand gripping at the blankets like he's holding on for dear life. "Wanna feel you come in me."
"Oh, I'm gonna come in you." He rubs his thumb, huge and calloused, over the sensitive little knob of Sam's dick. "Gonna -- fill you up with come, baby boy."
Just like that, Sam loses it, curling in on himself as his cocklet jerks in Dean's fist. Every jerk, every twitch seems to grip around Dean's cock, muscles flexing and pulling tight.
"Yeah," he groans, sliding his hand up to rub through the mess of jizz on Sam's chest. He can palm the whole fucking thing, pinning him there like that while he fucks up into him. "Yeah, you like the sound of that, huh, Sammy? You want me to fill up your ass?"
"God -- Dean." He sounds dazed, but nods, curls going messier on the cotton sheets, and that's all the permission he needs. It's harder than he's come in years, probably, balls jerking out string after string of jizz in Sam's tight little teenage hole.
He's careful not to pull out when he rolls to the side, pulling Sam along with him.
"I can feel it," Sam sighs, nuzzling against his cheek. "I can feel your load in there. It's warm." He blinks, looking like he's already lazing on the edge of sleep, and then grins slowly. "I'm takin' it all right now."
"Like a big boy," Dean says, pulling him against his chest.