Oh, just one item to append to my "keep him around" thoughts: he dumps the chick immediately as well. Otherwise, forget it.
I forgot your previous threads, so I just went back and read them now. (BTW, they are
Once a cheater, always a cheater? and
How to discuss issues with girlfriend, constructively?). She's only been around since April. Everyone in the other threads told you to get away from her, and for some reason you wouldn't. Sure enough, the shit came down. Live and learn, find a better woman next time.