I feel sort of like that about my ex. I didn't marry the guy, but we were together 6 years and lived together, so damn close. No kids together, thank goodness.
After he broke up with me (or shall I say, during the protracted breakup) he began a relationship with an older woman, married her, had two boys with her, then they split up and he was arrested twice for harassing/stalking/scaring his kids - evidently he had a habit of getting drunk and showing up on the doorstep, screaming at them. He was unemployed for a while and now to the best of my knowledge lives with his older brother.
I feel so bad for him - part of me still sort of loves the guy, as he never did anything really bad to me. Yeah, he was a little mentally unstable, but not abusive particularly. Kind of a lost little boy who never had anyone worthwhile to guide him (sniffle) and had issues with his parents, an oh-so-loving Catholic family that made no secret of the fact he was their "oops" kid.
I haven't seen him in 18 years but I hear about him now and then through the grapevine. I keep thinking, if I'd have stayed with him and stuck it out, he'd be happier, more successful. But realistically I think he would have just dragged me down along with him.
