So what should I do now

So 3 years ago I had sex with this boy let’s just say he liked me a little more then I liked him he wanted me to be his girlfriend and all but later I found out he was married and he had a baby on the way and there was no way I’d be comfortable because he lied so when I cut ties with him he got mad and started talking about

Me at work trying to make me look bad but behind co workers back he’d talk to me like he wasn’t mad so still to this day he likes me and he even blocked me on fb after I denied his friends request what do you call this I just want to tell him why would I be with a cheater some one that talked badly about me and the mother of his child