The dust falls back into its old places, maybe finds some new ones, the scorching desire abandons all air, all joints. And everything goes awkward. There aren't many things to say post factum, not about the most immediate past. Dean doesn't tell Cas he's so relieved he's almost alive. Doesn't inform that an angry spirit is for now banished out of him, doesn't say fucking (two entities, to be honest) felt like his bones were being scrubbed dry then draped over with flesh, blood and skin once again in some kind of phoenix-cliché act of burn and rebirth. Judging from the noises he was making, from his heavy, labored breathes, from the calm on his flushed face – Cas can probably tell with no words.
His mind hasn't been this clear in weeks. That's why he's now got it in him to outdo himself in ruining the post coitus mood because he sees bright as day the scale of the quicksand of shit Cas has dragged them into. He lets anger stir inside him silently until Cas leans down in an attempt to kiss his split lip (like it's some kind of war trophy). He doesn't get to do that cause, frankly, now that the sex lens flares stopped confusing him, he's pissed about Cas striking him like that this thoughtlessly. Pissed, cause he thinks about the first time he beat him up into mutt chow. And about the other time. The very foundation of this idiocy leads to the second reason why Cas doesn't get to do that and this is something he's going to talk about right now. He pushes Cas's head away in an ugly, demeaning gesture. He decides to start with, "Fuck off, you stupid son of a bitch."
Luckily for him, Cas stays in his shitty lane and doesn't try a second time. But he squints, clearly not getting what he's done wrong. Well, Dean's gonna explain that.
"Why can you never control yourself? This isn't what I gave you the blade for. You didn't wanna kill me? Fuck you, fine. But if I knew you were going to condemn all of us to something worse than dying, I would've given the damned thing to Crowley. At least he can keep his mind straight!"
"Dean," Cas begs, "this is the only thing I could have done to help you," he explains. "Sam and I are running out of time."
"Yeah," Dean huffs. "Now you really are, no way of stopping it."
"A compromise to your thirst is the only solution we have. When Sam called, I was forced to act quick. I'm the only barrier strong enough to stop you from getting your hand on the blade and this, this form of relief will let you stay sane."
"No, it won't. And it's gonna destroy you from the inside. It already seduced you into taking it near me. Just how it wanted to."
"What was I supposed to do, then?" Cas thunders, incensed. "Let you slowly descend into madness?"
"So you decided to speed it up instead?"
"That's not how it works."
"That's exactly how it works, Cas," Dean sighs. "Been there. After each contact I got better only to cuckoo later. This is contact enough."
"I'm buying us time," Cas insists. "Sometimes-"
"Love is a battlefield, you heard that in a song once, yeah, I remember," he interrupts tiredly. "You just picked the worst weapon. Literally."
"So if it's the dumbest way, we'll just stop," Cas shrugs, "and keep looking for something better."
Dean laughs at him bitterly.
"You really don't get it, do you? Cas, I'm past that point," he murmurs, rubbing greedy circles over Cas's belly. "I'm not gonna stop. Neither are you. Give it time, it'll call. We'll fuck like rabbits each time until there's nothing left of us but sulfur."
"We'll find a way."
"There is one. Shoot me with a gun while it still can kill me."
"No."
Dean laughs humorlessly. Nothing else he can do.