I'm sure they've said more, but those are the things that I think really pissed off Peter the most.
Sheree disrespected Cynthia last season towards the end with the talk of Cynthia being up NeNe's ass, not sure if that's what prompted Peter to go in on her or of something else went down. In the end all he said was he didn't think she was cute, it wasn't like he went all the way ham on her. We all know sheree has said worse.