Tony, like Nathan, has a past of violence and trauma. A person expressing rage at him is likely to frighten him away just as someone expressing aggression makes Nathan shut down. Different methods but similar reasons. Even if Tony was capable of breaking him before he turned into a demon, he never would.

"After that I think I need a good cartoon marathon. After sleep, you want in?"

Cartoons make everything better. He doesn't want to think too hard about how it could have played out, he just wants to forget Cesar's melted face. Horrific.