Why did Marianne constantly talk about her ex-husband?

Yes, she appeared to be the type that, rather than let a wound heal, would instead keep picking the scab off. It's not difficult to understand why there is no man in her life (if she indeed even wants one); the first date would probably consist of the same ex-bashing, which would grow old in a hurry.

I hate her character so much, there is nothing I hate more than people who don't stop talking about their exes. I learn always treat with suspicion to these kind of people, It is clear they many time bends the truth and hides their shortcomings.