Now.
Sam sat next to Dean in silence for a while, watching Dean down more whiskey every time his thoughts got close to what happened that night. He'd emptied his flask, and was now drinking from the half empty fifth he had found in the trunk. Dean couldn't help it, he felt awful! Eventually Sam gave up and turned to leave. Dean didn't even notice. His mind was numbly thinking about Cas. He wasn't gay. Of course he wasn't gay... Yet for some time now, Dean had had dreams about him and Cas... dreams that got him a little hot under the collar. Not every day, Hell not even every week, but they were a reaccurring thing. At first Dean had written it off as sexual frustration and too close quarters, but when the dreams had come while neither was an issue, he had tried to forget them even more. And it worked a bit, but then he would have another dream, and the resulting morning wood always forced Dean rub one off in the shower. The shame burning in his gut would last for days, and then it would fade. Until the next dream. Dean hit the bottom of the bottle, and still he couldn't forget how the succubus posing as Cas had his fire stoked in no time, when every woman it had tried didn't even light a match.
Earlier this night.
Sam recovered first and shot the succubus with his gun. The special bullet peppered it with sizzeling holes that swiftly grew and burned the screeching monster up. Cas kept flicking his gaze from Dean's lust flushed face to the heap of ash that only recently had looked like him. He cleared his throat. "Dean..." Dean surpressed a shiver at the gravelly voice. He couldn't do it. He couldn't face Cas, or Sam for that matter. He felt the fires of shame burn his cheeks, even as his cock strained against his jeans. He pushed past his brother and Cas and ran outside on his socks. He heard them call back at him. Both voices rang with concern, but Dean didn't stop. He couldn't. He ran to the Impala and dove behind the wheel. The engine revved and Dean pulled out of the parking lot. As uncomfortable as it was to drive with a hard-on, it didn't lessen one bit, and Dean dreaded what he needed to do. He drove out of town and once he was well in the sticks, Dean pulled over.
With his Baby well hidden from view, the ringer on his phone muted, and the night deep and dark around him, Dean sighed and got in the back seat. The box of tissues and bottle of lube he had stashed were within reach and he made himself as comfortable as he could. He unbuckled his belt and undid his jeans. Palming himself through his boxers, he tried to imagine anything but what got him in this state to begin with. Flipping through the faces and fantasies of his spankbank didn't work in the least. He only felt the burn return when he pictured Cas. Even the most innocent memories fanned Dean's flames. Cas, smiling at Sam and him being dorks, Cas, fighting in that badass way he had. Dean arched his back and closed his eyes longingly. That was actually pretty hot.. no..don't go there... Cas trying to work out a reference Dean had made, Cas tilting his head in that adorable way he had. Wait... what? Had he really thought that? Oh god! Focus... Cas looking Dean right into his eyes, making Dean stare back... Cas tracing his lips up his neck... Cas kissing him... Dean moaned, all thoughts of keeping his fantasies Cas-less or none X-rated forgotten. He released his rockhard cock from his boxers and stroked it. He spread the precum, beading at the tip, over his cock and licked his lips. His mind wandered to Cas' lips and how they would look wrapped around his cock. Cas would look up with those amazing eyes and... Dean scrabbled for the tissues and only just put some in place before he came hard, harder than he had in quite a while.