Dean slipped one lubed finger into Cas’ hole and began to prepare him carefully. He always took his time with this part, stretching Cas slowly, making sure that he was ready and eager. He waited until Cas was pressing desperately back against his hand before he slipped in a second finger and then a third.
“Are you planning to actually fuck me?” Cas asked, his voice even rougher than normal.
“In a minute,” Dean said. He curled his fingers, pressing briefly against Cas’s prostate.
Cas moaned. “Please.”
Dean smirked. “Well, since you asked nicely…”
Dean withdrew his fingers and grabbed the lube, smearing a handful onto his dick. He moved forward onto the bed until he was kneeling right behind Cas and lined up his cock with Cas’ entrance. He rubbed the head of his dick up against Cas’ hole, making it shiny with a mix of precome and lube before guiding himself into the tight heat of Cas’ body. He tried to move forward slowly, but as soon as he felt Cas’ hole flutter around him, he lost all control and plunged in quickly, bottoming out with his balls slapping against Cas’.
He was already on edge after spending so long fingering Cas open, but he forced himself to wait, breathing heavily against Cas’ back. Cas needed the time to adjust to Dean’s cock, but Dean needed time, too. If he didn’t get control of himself he’d come too soon, and no one wanted that. Once his breathing was under control, he pulled back as slowly as he could and then thrust forward hard and fast.
The best thing about fucking Cas--well, other than the fact that it’s Cas and Cas is awesome--is that Dean can fuck him bareback with no consequences. Dean has always loved the way it feels to be sheathed inside another person without a condom in the way. He loves the slow drag of skin against skin, gradually building to the moment when he can’t hold back any longer and marks his partner inside and out.
Dean’s not stupid, though; other than a few teenage indiscretions, he’s always used a condom. The last thing he needs are little Winchesters running around or a funny rash that leads to an awkward trip to the clinic. Things are different with Cas though. Cas has never been with anyone else, and neither has his vessel since it was remade. He’s as clean as can be and Dean likes that. He likes knowing that he’s the only one who’s ever been with him, the only one who will ever be with him if Dean has a say in the matter.
“Harder,” Cas demanded, grabbing his own dick and beginning to stroke in time with Dean’s thrusts.
Dean didn’t have to be told twice. He grabbed hold of Cas’ hips, pulling him back onto his cock with each thrust, slamming their hips together.
“Dean,” Cas gasped, collapsing forward and resting his head on his folded arms.
The change in angle was more than Dean could take. He gritted his teeth and tried to hold out until Cas came, but he couldn’t. He thrust forward one last time and gripped Cas’ hips hard enough to leave bruises as he came. He came in waves, circling his hips as he poured into Cas.
Dean fell forward onto Cas’ back, breathing hard. He didn’t want to move, enjoying the feel of Cas' body around his softening cock.
“Dean?” Cas asked desperately, clenching his ass around Dean’s cock. “Please.”
“Don’t worry,” Dean murmured, patting Cas’ shoulder. “I’ve got you.”
Dean pulled away, his dick slipping free, and knelt between Cas’ legs. He took a moment to admire the firm ass laid out in front of him before smacking it lightly.
“Dean,” Cas nearly whined.
Dean chuckled softly and squeezed Cas’ ass gently before pulling the cheeks apart to look at Cas’s hole. He could see his come, white against the swollen red skin. It made his mouth water.
“So full,” Dean whispered. He trailed his fingers up the cleft, pushing the leaking come back into Cas. “So full of my come.”
“Mmm,” Cas agreed, tilting his hips up, bringing his ass closer to Dean’s face.
Dean grinned and leaned forward, taking the hint. He licked a stray drop of come off of one cheek before lowering his tongue to lick up the crease. When he reached Cas’s entrance he slowly circled the hole, occasionally darting his tongue just inside. He loved the taste of his own come, mixed with the surprisingly clean flavor of Cas. He didn’t know if it was because Cas was an angel or just because he usually didn’t eat anything, but he always tasted cleaner and fresher than he had any right to—not that Dean was complaining.
Cas whimpered and pressed back against Dean’s face and Dean took pity, spearing his tongue forward. He used his thumbs to hold Cas open as he fucked into him with his tongue, licking out as much of his come as he could. When he paused to suck out the last few drops, Cas shuddered and came, his body clenching tight around Dean’s tongue.
When Cas stopped shuddering with pleasure, Dean gently bit one cheek before moving to sit beside him. “Roll over.”
Cas didn’t respond at first, so Dean pushed him gently until he rolled over onto his back. He looked in disappointment at the wet spot on the bed before leaning forward to run his tongue over the streak of come on Cas’ stomach.
As much as Dean liked the the taste of his own come, he loved Cas' even more. Like everything else about him, it was almost like a normal human’s but not quite. Dean swore that he could taste the power of Castiel’s grace in his come, and he loved the way that flavor mixed with his own human essence. He moved down to take Cas’ soft cock into his mouth, not wanting to waste any. He sucked gently and dipped his tongue into the slit, relishing the last few drops of come before lying down next to Cas. He idly ran his fingers through the wet spot between them, occasionally bringing them to his lips.
“You are insatiable,” Cas said, watching Dean with that too intent stare that Dean had come to love.
“I can’t help it,” Dean said. “You make me that way.”