Can anyone give me some advice on this messed up deal?

So unfortunately my ex boyfriends Friends and my friends are the same people. Whenever there is a party we are always there together. Well last night he was being down right rude to me. I would offer him a drink and he would just say I'm not drinking anything you give me. Then this guy is like well if you do need to crash here you can always snuggle up to me and he said as long as that's the only one snuggling up to me. Then I was like oh I got to run to this guys house to get my french kiss (which is alcohol) and he's like whatever you just want to go hump him. And then I was on the couch with some guy and he walks in and said smack her *** she really likes that. Then goes into the other room and asks my friend "what is your friend cat trying to make me jealous or something" and she said, idk haven't seen her in a while. Then we were talking and he flips me off, and I said oh can you tell there's some hatred going on here? And he said there is no hatred here. So what the hell is his problem?? I mean he was attempting to get with this other girl and she dumped him for her ex boyfriend, and I know that he is really crushed and upset about that so is he lashing out at me for that? Is this like a love hate type of thing, or whats his deal? Much thanks :)