This seems to suggest that attacks are a completely disjoint category from humor and/or social bonding.

I suppose this might be a purely semantic thing, in which case I have nothing useful to add... that is, if you're just saying that if a friend does it we don't call it an "attack," even if that's what we would call it from somebody outside the group, that's fine.

But semantics aside, the same action can be both an attack and humorous and a form of social bonding.

Similarly, in some social circles fistfights are pretty common among friends. Such brawls are certainly attacks, but that doesn't preclude them also being good fun. All a question of what you enjoy.