"Shhh, Sammy, please," Dean runs his hand through Sam’s hair mindlessly, down his face, trying to shush him. "You have to relax, baby."
Sam knows this, really, but still can’t help the whimpers that escape him, the feeling of his brother’s big cock breaching the rim of his virgin asshole is too much. It feels like it will slice him in two. Even with the weeks, months of preparation, of Dean blushing high on his cheekbones and whispering in a tormented voice, “Sammy, I don’t want to hurt you.”
But he asked for this. Even as the burn tears through him, Dean pushing forward slowly, he knows that he wants this, he needs this. So, as Dean’s words tumble into his hair, he makes himself relax, remembering the times that he and Dean had done this before, with fingers and tongues and a vibrating butt plug that made Sam squirm and blush red when Dean had pulled it triumphant from his jacket pocket, swiped from the adult bookstore down the road, remembers the toe-curling sensation that accompanied each press against his prostate, and finally, Dean meets no resistance as he slides all the way home, grinding his hips against Sam’s ass with a whine deep in his throat. “Damn, Sammy,” Dean gasps out.
Sam can’t breathe against the stretch, the buzzing in his skin at the fact that his brother is finally seated hot inside of him, after all these years, he finally has Dean in all the ways he needs him. He makes himself go liquid as Dean rearranges the pillow under his hips, the action pressing him all along Sam’s insides. Sam gasps, mumbles nonsense, and Dean leans down to kiss him, caressing inside his mouth with urgency.
After what feels like hours, Dean surfaces, flicks his tongue across Sam’s lower lip and asks him, “Are you okay? Did I hurt you?” His eyes assess Sam’s face in an instant, taking in the pained pinch of his face, the red of his bottom lip as Sam takes it between his teeth, bites down hard.
“I’m fine, Dean,” he grunts, before locking his ankles across his brother’s lower back, forcing him in harder, and Sam can’t control how dark with lust his voice is when he says, “Now, move.”