Dean nods. That actually makes sense- Not that any of this really makes sense, but for what they're used to? Yeah, he can wrap his brain around that just fine.

"So what do we do here?"

And he tries not to sound like he's kinda twitching to get away from Sam now that they're both alive and well, but he knows Sam's gonna see right through that. Not that it matters. They're just "peachy". That alone should explain why he's not running to give him a hug.