That got a laugh out of Adam, not at his brother but at the absurdity of their situation -- only the Winchester brothers would be able to say any of the things they were saying at the moment.
Oh, alright, and probably half the other residents of the hotel, but they weren't important at the moment.
"I'm not sure where Michael and I were taking off to, I just know he needed to get away. Maybe we went somewhere he could finish that existential crisis in peace or something. Because man, he reacted to the whole douchebag parent thing even worse than we did."
Because he knew by now it wasn't something Dean liked acknowledging, and he himself certainly hadn't enjoyed realizing just how badly John Winchester had fucked him over.