Technically it is still considered abuse. It looks bad on the server but people do it all the time. Like Joker said, the other person has to be okay with it. A slap at the end of the round to a buddy isn't a big deal really but if you take it too far it starts conflicts.

I'm sure it is abuse but do I think Zero or clan members will act on it? Probably not. Unless is goes beyond a reasonable limit..