Sam having a pillow/mattress humping phase when he was a teenager. And Dean knowing about it and sometimes teasing him, but not really blaming him because there's not many ways to get off stealthily when you're a horny teenager in a motel room.
One day when they're older and sleeping together, Sam wakes up with a raging boner pressed to Dean's thigh. He shifts away but his hips stutter at the slightest friction. Then he feels Dean's hand at his waist, holding him steady, and his brother's eyes are looking down at him with lust.
All it takes is a little gentle encouragement, "Go on, Sammy," to get him to roll his hips forward again. His clothed cock ruts against the muscle of Dean's thigh and he groans, dropping his head to his brother's shoulder as he humps his leg. Dean's fingers tangle in his hair and rub soft reassurances while his other hand rests on Sam's ass and pulls him closer with every forward thrust. And soon Sam's leaking through plaid cotton, breath hot against Dean's clavicle with each little muffled moan, and it makes Dean's cock ache but he ignores it. He knows Sam will take care of him after, happy and eager in a post-orgasmic state that somehow makes his mouth feel even better when wrapped around Dean's cock. And it won't take very long. Sam's hand slots between them and he adjusts himself to get his cock positioned perfectly between their bodies. The constriction of the boxers holds him in place as he ruts, hand moving to hold Dean's chest, hips bucking faster and faster with quick little thrusts.
It kind of reminds Dean of an actual dog, or the kind of primal chase for release you'd see on the discovery channel. Sam pumps away like a rutting animal and Dean lays there and takes it, encourages it, ruffling Sam's hair a little. "Attaboy," he even whispers, and his cock throbs at Sam’s drawling whine in response. The keening soon devolves to panting as Sam fucks at his leg and Dean pulls him closer, goading him to orgasm. "C'mon Sammy. Little bit more. That's my good boy..."
And Sam shakes on top of him as he comes hard and hot in his boxers, thrusting erratically and letting out a series of noises that border between whines and moans. Dean feels the sticky mess leaking between them and presses his thigh into it, helping push Sam through the last waves of his release since his brother isn't doing much more than bucking into the sharp spasms of the orgasm wracking his entire frame. Sam's breath is hot and his tongue laps softly at Dean's neck with another quiet whine as the sensations slowly abate. Dean smiles to himself and tousles Sam's hair again.
Part 2 of the Winchester Wake-Up Series Now on AO3














