I think it's also the why Sam is doing what he's doing on top of that. Sam is Dean's good thing. He's the one thing that Dean feels he's really done right (he raised the kid, after all), and Sam turned out better than okay as far as Dean was concerned. He still had the heart and the empathy, and all those things that were important for a person to have. And he went to Hell, and he came back changed, and I think he knew that Sam was going to change too, but he didn't expect it to be quite like this. I think he hears Sam saying that he's trying to do it for him, but he doesn't want it like this, he doesn't want his good thing turning into a monster like him.

Well, the one version of Sam who's got a baby on the way doesn't know about the demon blood? So -- he's not really thinking about that? But still -- we're workin' on it.