Dean can mourn Cas. He's gotten good at it. That's the problem.
Cas is alive. Really alive, in a way he's never been before. Human. And no, no, that is not the problem. That's not a problem at all. It's weird. It's really weird having him around—really around, like all the time. Like no more zapping off when Cas decides he's going to do whatever the hell he wants. He's not making those kinds of decisions anymore, anyway. Dean's convinced Cas doesn't know what he wants, at least outside of making a pest of himself.
"Could I, maybe…" They're heading back to the car and Cas has got that look in his eyes, like he doesn't want to be a bother but he doesn't understand how curiosity kills the cat, so he's going to ask and ask and ask. Except right now, he can't quite get the words out; and Dean doesn't piece it together until they're standing next to the Impala.
Then, Dean's face lights up and he laughs. "No, no-no-no-no-no. You are not driving my car."
Cas can't grasp why it's funny. All he's hearing is Dean telling him he's incompetent. "Dean, I've read every—"
"You wanna learn to drive," Dean says, smiling bitter, "take a class." Yeah, like that'll ever happen.
Cas throws his hand on the driver's door before Dean can get it open. The midday sun burns in the metal, but Cas doesn't flinch. He hasn't grown a fear of injury, yet; and maybe he never will. Maybe they'll just have this argument a thousand times. "You don't trust me."
It wasn't even a question. They both know the answer. The worst part is, neither of them is surprised.
"Give me a chance. I won't screw this up." Cas is so sure, and Dean is so unfazed. They stalemate for six seconds and then Cas pulls his hand away. He's surprised when the sting doesn't quit, enough to glance at his fingers. "Flight is much more complicated than driving a car," he adds, and it's a good point but his commitment is shot. He's not so sure of himself anymore. Whatever he is, anymore.
Dean pulls the door, and as he's dropping into the seat, he just mutters, "not today." It's the absolute best he can do right now. He's not ready to give Cas a way to zap out on him again. It's wrong. Dean knows it's really wrong, but he needs Cas to stay for now. Dean needs to know Cas will be okay.
Because when he goes—when Cas finally goes—Dean's got this sneaking suspicion that he won't be able to feel it. He won't be able to feel anything. It's a beating he's taken too many times, and it just won't hurt like it should. And it should. If it's not a break in his chest, it's a burn in his throat. He's been down this road so many times. Dean knows how to mourn Cas. It's just that he's gotten good at it. That's the problem.
Cross-posted from AO3, May 20, 2013