Maybe a better word is sh!tty. As in "my ex is a pretty sh!tty" person. And i am not gonna sit their and come up with explanations for it like foo issues, or maybe he was dropped on his head. Because it doesn't matter.
I think a person capable of lying, betraying, cheating, stealing to/from their own family has to be sh!tty. These actions are pretty black and white no? It's not like there is a gray moral ethical issue they are forced to make a decision about like "hey I'm gonna steal some bread so my kid can eat" .
Oh I think there are a whole lot of shades of gray here. My ex for example, I think what it all boiled down to is she changed and no longer wanted to be married. So is she sh!t? She's a great mother to our kids, she's a kind, helpful person, and despite what we went through I still think she is a very selfless person. She did what she did because she felt there was no other path to happiness.
In some other cases people's spouses go through something, call it MLC or whatever but it can be temporary. They do crazy, sh!t things and even hate themselves for it. But eventually they get past it and return to their normal un-sh!t selves. These are the tough cases because you simply don't know if they are going through something temporarily or not. I mean you would never, ever leave your spouse because they got sick, yet that is exactly what this might be- a sort of mental sickness that they will eventually recover from.
In yet other cases there are previously good people who mysteriously turn to sh!t and they never do turn back again, they stay that way for good. That's in direct contrast with the above, because there is no recovery. So you can wait forever for them to "recover" and they never do.
And then there are those cases where the person was sh!t to start with but blinded their spouse-to-be with fake behavior, then once they got married the sh!t began. It wasn't because they changed, it was because they were acting all along and now their true self is showing through.
Part of the challenge in DB'ing is figuring out which you're dealing with, LOL!