A/N: Okay, so this is my first attempt at Destiel smut. Not something I was expecting to write but my muse was very insistent at 3am. The first line of dialogue is from 6x21 although I changed the timeline just a bit so they're in private when he says it and not Lisa's hospital room.
"Dean, I said I'm sorry and I meant it." Cas said, his gaze falling anywhere but on Dean.
Suddenly he could feel his back being pressed against the wall, and Dean's breath ghosting against his ear.
"I don't think you are, but you will be." Dean whispered, before forcefully taking his mouth. Cas felt a shiver down his spine as their tongues duel for dominance. Seconds pass before Cas's inexperience forces him to surrender. Too soon, need of oxygen forces Dean to break the kiss. As he stood there pinned between the wall and Dean's body, panting for air he technically didn't need, he could feel the lust following through his veins, felt his body react to Dean's dominance display.
He watched Dean's eyes and the slight smirk that appeared right before Dean's mouth found a sensitive spot behind his ear and Dean's knee made its way between his legs. His hips, seemingly with a mind of their own, bucked against Dean, grinding his hardness into Dean's thigh. He groans first in pleasure then in frustration as Dean's hands find his hips and hold him firmly against the wall.
"No." Dean whispers. He presses his mouth against Dean's, desperate for something though he's not quite sure what that is. He feels Dean pull him along as he walks backwards toward the bed, then falling as Dean pulls him on top of him. He doesn't even have time to orient himself to their sudden horizontal positions before Dean flips them over so his back is flat against the mattress and Dean is straddling his hips.
"I want you naked now." Dean demands, before leaning down and attaching his mouth to Cas's neck. With a thought, his clothes are gone and "Oh my…."he moans at the feel of Dean's jeans against his now completely hard cock. He feels Dean slide down his body, leaving a trail of hot kisses and love bites along his chest and stomach.
Dean stops when his mouth reaches where the waist of Cas's pants would have been and catches his eyes, where Cas is sure he sees the lust surging through his body. He instinctively knows Dean is searching for something though he's not sure what that is. Apparently he finds it, and smirks as he wraps his index finger and thumb around the base of Cas's cock making a rather crude cock ring before his tongue snakes out to follow the vein on the underside of Cas's cock. His eyes drift closed as his body feels the liquid heat of Dean's mouth and the sensations build hotter and hotter until minutes later he experiences his first orgasm.
He whimpers as he feels Dean pull away from him as he's still painfully hard, having not been allowed to cum. Minutes later, Dean returns naked with what appears to be an actual cock ring and a bottle of lube. He makes quick work of wrapping the contraption around Cas's cock and balls and Cas half whimpers, half groans at the pressure being exerted on sensitive area.
"Turn Over." Dean orders. Cas knows the look he shoots Dean is wide eyed and curious as he flips himself over. He feels Dean once again straddle his hips and attach his mouth to the place where his neck meets his spine. Slowly Dean moves down his body like before, however unlike before he stops so he is gently nipping at the spot where Cas's wings meet his body. He cries out at the pleasure that this sends through his body causing his wings to break free of the hold he has on them and spread out as much as they can in the small room. He feels slightly embarrassed at his lack of control but it is immediately forgotten when Dean runs his hands over his feathers while continuing to nip his skin. Soon the sensations begin to build again, climbing higher than they had before until yet again his body orgasms without being allowed to cum.
Dean pulls away slightly as he slides further down Cas's body. He felt Dean's hands on his ass, pulling gently until his entrance was exposed. His hips began to buck into the mattress as Dean's tongue delved inside him. He whimpered when Dean pulled his hips up and away from the friction the mattress had been providing to his aching cock. Pulling his mouth away, Dean asked,
"Do we keep things from friends?" Dean asked.
"No." He moaned.
He felt Dean plunge a finger into him.
"And do we make deals with Demons?" Dean asked.
"Dean!" he cried out, with some pain but mostly in pleasure. Soon, two fingers in, Dean found his prostate.
"I trusted you" Dean said.
"I'm sorry." Cas gasped.
"Are you?" Dean asked, pressing harder against that bundle of nerves.
"Yes, Dean. I'm sorry. Please!" Cas begged. Dean scissored his fingers several times before finally adding a third finger.
"Dean, please!" he cried out again. He moaned as he felt the loss of Dean's fingers.
He heard Dean moan before he felt the head of Dean's cock at his entrance. He grimaced slightly as Dean thrust into him as he pushed himself to his hands and knees, unfurling his wings at the same time Dean's hand came down and replaced the leather cock ring with the crude one made with his fingers.
Not long after he felt Dean swell slightly within him, he felt Dean's free hand go to his wing while the hand wrapped around his cock pumped once, twice, finally a third time before he came screaming. Seconds later, Dean shouted his release. Once the tremors stopped, both men collapsed and Dean quickly rolled his weight off him but holding him close as they both panted.
Once he'd finally his breath, he turned so he could look directly into Dean's eyes.
"I am sorry, Dean. I never meant to hurt you or break your faith in me. I truly thought that was my only option."
"I know. I just wish you'd have come to me. You knew you needed help, and you knew it was wrong or you wouldn't have kept it from me." Dean said.
"I'm truly sorry Dean. Can you forgive me?" Cas asked.
"You've already been forgiven Cas, or you wouldn't be where you're currently at. Now, I know you don't need sleep but I could use a nap so can we please end this goddamned chick flick moment." Dean said.
"Dean." Cas warned. Dean just rolled his eyes and smirked.
"Fine", Cas sighed, "Sleep Dean, I'll be here when you wake up."