That feeling was your intuition, your gut telling you to stop letting him contact you anymore. He screwed you over enough to be with this bitch he can't seem to let go of. Why would you want him even talking to you? Leave sleeping dogs lie and don't answer any more of these crumbs he's leaving for you to see if he can wheel you back in once again while he's inbetween girlfriends.
I don't know either of you but I know enough to tell that this guy is a loser and you're too good a person to let him back into your life.
“The willingness to accept responsibility for one’s own life is the source from which self-respect springs.” ~Joan Didion