Ummmm help me please?

Okay this guy that I like (lets call him Bob), I talk to him alot and he`s really nice to me. But another guy I know told me that he was talking to Bob on the phone and told me Bob called me a dumb b*tch. I don`t understand why he would call me that because I`ve never been rude to him or annoying. But I think the other guy might be a bit jealous of me liking Bob. Then after I asked him if Bob actually called me a dumb ***** and he said "pretty much". What is 'pretty much' supposed to mean? Do you think he actually called me that -__- !?