It doesn't matter who they are, actions not words.
I had a bpd (undiagnosed) plate a few years ago who used to throw huge tantrums at times, waterworks, "you're a cunt" etc., acting cunty in front of people. Shortly after she realised that I wasn't going to give in, it always stopped. It's weird. It's so believable too, chicks like that are fucking maneaters.