Any other time and Sam might be more focused on wet, naked Castiel. If he's allowed. But right now, Castiel is a friend and hurting and that's all that Sam is going to let himself think about.

"You don't have to repay me, Cas," Sam says, wiping the towel over Castiel's hair again, almost amused at the way it won't quite set down, even when wet. "You're my friend. That's all the reason I need to help you."