my biggest pet peeve is people that create a character that is "all knowing". By this I mean when a person's character has a secret that they haven't told anyone yet and has only been mentioned as a thought bubble and another character calls them out on what the other character thought. Mind you this was in multiple rps where there were no super powers were present.

Now if a person just accidentally read a thought as them speaking that is understandable, that can be solved. I've done this, but I just don't like it when some ruins a secret that was going to be used as something to shock the characters.