Written for Phantisma's Comment Porn a Day on LiveJournal. I'm still working on my porn writing abilities, so don't roast me on a spit.
Also: WARNING. WINCEST.
Dean had never pegged Sam as an exhibitionist. Sure he liked to mark Dean up, a bite here, a bruise there, show the world what was his. And Dean liked it, because he got to show the world what was Sam's. But he never thought that Sam wanted to show the world exactly how Dean belonged to Sam.
When they left the diner, satiated and ready to go back to the motel, Dean hadn't even thought about it. Just leaned over and pecked Sam on the cheek. It wasn't his thing, but Dean was just so relaxed, and honestly? Who the hell gave a flying fuck?
What Dean hadn't counted on was Sam's reaction to the kiss. A bulge instantly sprang up in Sam's jeans, a blush expanding across his face. He couldn't resist reaching up and grabbing Sam's hair to tilt his lips, and planting a lewd kiss right there in the parking lot.
He was also unprepared when Sam crowded him against the Impala, sucking at Dean's neck and pressed so close that Dean could feel his brother's erection.
The next thing Sam went for was Dean's belt, and come on, the diner was right there, not even five yards away with its glass windows. Anyone looking outside would get quite an eyeful. Dean reached down and grabbed Sam's hands.
"You're joking right?" Dean tilts his head towards the diner.
Sam looked at him, imploring, hands not moving away from their target, and if anything they're creeping closer to the buckle.
"Dean," The yearning in Sam's voice damn near breaks Dean's heart, and how can he say no to those fervor filled eyes? Like it physically pains Sam to not ravage Dean right that moment.
Dean relaxes, and Sam's hands move faster, belt flung open and zipper down before Dean knew what was happening. Sam went down on his knees where Dean's own erection rose greet him, and licked the head, taking the opaline droplets into his mouth.
Dean looked down at his brother and grabbed Sam's hair, something to hold onto because otherwise his legs were going to buckle and wouldn't that just ruin the moment?
Sam had never opted to give Dean a blow job, and yet here he was in front of Larry's Eat-In opening his mouth and gently sucking on Dean's dick, and looking like the highest person in the world.
"You like showing people Sam?" Dean tugged on Sam's auburn hair, carding through it.
"You like to let them know I'm taken?" Sam moaned around Dean's cock, the hand not pinning Dean against the Impala palming at his dick.
Sam's tongue moved underneath Dean's shaft, jaw working a little wider to take more in. Dean couldn't help his tiny thrusts, refraining from just seizing Sam's hair and full on face fucking him.
It wasn't new for Dean, he'd gotten blow jobs before, but this was his baby brother, down on his knees and lips wrapped around Dean's cock while he himself was moaning like he was the one getting blown. It was just so goddamn obscene.
Sam was gently using his teeth to slide down Dean's dick, pressing his thumb into his brother's hip, and saying something around the cock in his mouth-
The second Dean realized Sam was moaning his name he came.
Dean shot into Sam's mouth, and Sam just swallowed it all, eyes closed and saliva dribbling down his chin. Dean's cock jerked again, and he keened, "Sam," Hands gripping tight onto Sam's hair, maybe to tight, but Sam didn't seem to care when his eyes flew open and a dark spot bloomed on his jeans.
Sam pulled off Dean, the loss of that warm heat striking, and Dean tucked himself away while Sam stood staring at the diner.
"Goddamn." Dean was still panting, and an even deeper blush spread across Sam's face.
"Get in the car you flaunting bastard." Dean rounded the hood of the Impala, a lazy grin in Sam's direction.
"We're finishing this."