Sam hadn't even... stopped to really think about what would happen when they found their dad. He knew- he wasn't letting John hurt Dean, not if he could help it. Dean didn't deserve that, he hadn't done anything and he was managing it. He didn't stop to think about what Dean would do either.

Sam was very pointedly not looking at Dean. He couldn't have any improper thoughts because of that blood or whatever if he didn't look, he figured and he didn't want to chance it to see if he even would think... things about Dean. Not right now. He got up to grab his jacket, slip back into his shoes since they'd be going out again.