Sam watched Dean carefully, held onto his shoulders with a death grip the first time they had sex.
He was only thirteen, he felt as delicate as a baby bird in Dean’s hands when he stripped him out of his pajama pants and underwear, freed his own cock and started circling it around the wet hole between Sam’s narrow legs. Dean’s hand had been down his pants before, more than once, and his fingers slid in with ease when Sammy allowed it. He just wasn’t thinking when he did it.
Dean tried to ease his way into Sam, but the entire journey in was rough. It felt like Sam’s pussy wasn’t a normal canal like he’d been anticipating, but a waving line that his cock couldn’t quite move in sync with. Every little push in made Sammy whimper, made him tighten his grasp on Dean and, worst of all, made him start to cry.
“I’m so sorry,” he apologized as he started to pull out, only making Sam cry harder.
“Just put it all the way in. It hurts when you try to pull it out.” His massive, watery eyes only made Dean feel like more of an asshole than he already was, taking his little brother’s virginity.
He abided by his request, maneuvering himself in every direction until he felt like he’d reached a complete dead end, unable to stick his cock in any further. Sam’s leg was drawn up, he almost looked scared as he stared in between their bodies and saw where they were attached. He was starting to turn pale.
Sammy was way too young for it, Dean didn’t like to admit that he’d fucked up but he couldn’t avoid how much easier it would have been if they waited at least until Sam had supplemented his bare bones sex ed course with his own research at the library. He was clenching so tight Dean felt like he couldn’t move, his thighs were shaking and he struggled to keep his tears at bay as Dean tried to pull his hips back and thrust into Sam.
“Ow! Dean,” he whimpered, “Dean, it really hurts.”
Guilt crashed over him so fast his head was spinning, and no rational thought process was happening. He knew in hindsight that he should have eased himself out, should have found something to try and lubricate himself to minimize the damage to Sam’s absolutely virginal vagina, but all that was repeating in his mind was that he was hurting Sammy, he was a fuckup and he was causing his little brother unnecessary pain.
Dean pulled his hips back, he tried to ignore every pained squeak and whine coming from Sam, and thankfully it ended when he tumbled backwards on the bed. He could see out of the corner of his eye that there was a smear of red on his cock, shame twisted like a knife in his gut, and it was only made worse when he saw Sammy curling up, pressing his face into his knees and jerking with silent sobs.
It might have been best to leave him alone, let him self-soothe as best as he could, but Dean crawled back up the bed and took him in his arms.
“I’m so sorry, Sammy,” he said against the top of his head, his lips brushing against his hair. “You’re leaving me with blue balls here, but you did so good for your first time.”
It took a minute for Sam to react, but the very small laugh he got out of him was better than actually getting to bang Sammy would have been.
At least, that’s what Dean told himself while he held Sam close and kissed the top of his head.