One of my wife's friends has a relationship like the one you just described... although those two have a kid (he's never paid a dime of child support) and live in different states, the jackass still finds ways to make her miserable despite the fact he's a 10 hour drive away.
I just can't comprehend why anyone would keep in contact with someone who was abusive or obviously incompatible.
Threads like this make me thankful for my wife