He shudders at the sound of Sam's whimpered begging. He shouldn't be doing this; he shouldn't love the sounds of Sam moaning as he twists and flexes his fingers inside his baby brother's hole. Sam's only fifteen, one would think Dean knew better.
"Dean, come on already. I want to feel you."
The older boy chuckles at his brother's impatience. "Nuh-uh, Sammy," he says in between placing butterfly kisses on the inside of Sam's thighs , "if we're gonna do this, we're gonna do it right. I don't wanna hurt you."
"You're not gonna hurt me," Sam huffs. He looks so sweet, so beautiful peeking at Dean from underneath his brown bangs. "You'd never hurt me." There's something about the way he says it, with such certainty and conviction that shakes Dean to his core. Gently pulling his fingers away, the older boy moves up the bed, placing loving kisses and soft bites on every inch of skin he can until he reaches Sam's lips.
"God, Sammy. You're just so fucking perfect. So gorgeous."
Sam allows his brother to kiss him for a while, enjoying the tenderness between them, before pulling back. "Okay, yeah enough with the chit chat." He pushes his hips up to meet Dean's still boxer clad ones. "I want you."
Dean wants to tease his brother more, but can't find it in himself to. This may just be only Sam's first time, but the heavy emotion in his chest feels so new to him.
He doesn't just want to fuck Sam, he wants this to be special. Giving his brother one last kiss, Dean sheds his boxers in one swift move. "I love you so much, Sammy. Always gonna be mine" he utters in the most reverent tone, as he slowly, carefully pushes into his brother's entrance.
Sam's moans wash over him like water. Dean has to fight to keep his eyes open, so he's able to catch any flicker of the pain that might come across Sam's face. It seems like it takes forever until Dean bottoms out, until finally he's fully seated inside. He fights to keeps his hips rigidly still then, despite his natural instinct to thrust. "You okay, Sammy?"
"Yeah, you're just...a little bigger than your fingers."
Dean can't fight the smirk forming on his face. "A little?"
"Uggh, shut up!" Sam gives Dean's chest a slap. "And move."
Dean examines his brother's face one more time, just to make sure he was okay, and then he begins to lose himself in his brother's heat. "Fuck, Sammy. So good."
It doesn't take long for either boy to come, Sam is first, with Dean's hand wrapped loosely around his dick, and lights bursting behind his eyelids. Dean follows immediately after, fully indulging in Sam's fluttering muscles.
"So, as far as first times go, how was it?" Dean murmurs into Sam's hair. They're both sated and sleepy, wrapped up in one another.
Sam raises his head to meet his brother's eyes. He places a soft kiss against Dean's jaw and whispers back, "Perfect."