Divorced the first time due to bedroom chemistry issues (we married very young, and our divorce was mutually agreed upon and we're still friends).
My second marriage was entered into in haste and led to much misery. I felt I was damaged goods who no one would want if I left him, even when he became EA and started getting into sexual kinks I didn't like. He lovebombed like crazy at the start of the relationship and ended up having a history of psychotic episodes he didn't disclose until we'd eloped.
Soon after we married, second husband did a 180 and my life felt like it was in freefall. He isolated me from family and friends. Our relationship had deteriorated to the point where I felt like I was more of his psychological caretaker and sexual outlet than a wife -- he had no respect for anyone but himself and made himself the center of the world, and had no intention of ever working another paying job (he told me this himself), but wanted to "unschool" children by having them run around unsupervised all day while he presumably did his usual, which was video games and television.
Meeting my now-DH while married to second husband was a fraught time because I thought there was no way it'd work out really. Now-DH was, at the time, living with a girlfriend who had been out of work for years and persuaded him to pay for course after course and scheme after scheme to make money, but of course it never panned out. He was depressed but working 3 jobs to keep paying her way.
When we had to figure out trust early in the relationship, it wasn't easy. Working through it together was some of the most valuable time I've ever spent in my life. We are deeply committed to one another, feel like we came through a hellish time in our lives by finding one another, and have our second child on the way. My DH has been a true partner to me in every way, an involved and engaged stay-at-home parent who has enabled me to get multiple raises and promotions since first falling pregnant with DS.
It's a little embarrassing to talk about how we got together, and it's true we often omit the part where we were both with other people. You'd have to have been in one of the relationships in question to have understood how down and taken advantage of we both were feeling at that same time.