What should I do with my boyfriend?

I caught him with a hooters girl the other night and I am devastated he was doing stuff that I don't even want to talk about he said that I was dreamy and that I was crazy but I could swear that I was awake so I went up to the girl and threw a beer in her face my boyfriend pulled me off and I said am I dreaming now and he took my hand and we ran and never went back and he has a history of cheating but when its good and were together we are so happy but when were in arguments he just does the most stupidest stuff what should I do.