And what would happen if those relationships hadn't failed exactly? Or worse what if your relationship with the person you married failed due to one of the extramarital ones?
You think you're making a point, but you are not. What if her marriage failed anyway for reasons completely discrete/divorced from any extra-marital relationships, or none existed?
For the record, almost none of my extra relationships failed. One became obsessive, possessive and stalked me a little. One just turned out to be a giant asshole once the sexual aspect of things had to end. But other than that, all have remained friendly. The relationships didn't fail; they changed. I wanted to go back to being monogamous. My marriage didn't fail because of any outide activities. It failed because my husband wasn't sexually attracted to women.
Some of my extra relationships remained strong and intensely sexual for a number of years. If I had not gone back to monogamy, I suppose I would have just kept fucking them or Wed have eventually drifted apart. I loved some if them, sure, but I always went home to my husband, and was not tempted to leave him behind.