Although I never condone cheating, and all the lying and betrayal that goes with it, the fact that these guys were involved with other women doesn't necessarily mean that they didn't still love their wives as much as ever. We have this silly idea that comes out of fairy tales that if you really love someone you will never be attracted to anyone else, and that just isn't the way human beings work. Of course, it would have been much better if they had A) never acted on those attractions or B) had a tough conversation with their wives about wanting to become consensually non-monogamous but that unfortunately isn't the world we mostly live in.
Men have really only been expected to be monogamous in the past 200 years or so, and they haven't exactly adjusted to that (and women are even less "geared" for monogamy than men are in that they often get sexually bored with the same partner within the first year of living together ). I think we need to recognize that and normalize other relationship options other than the serial monogamy that is so prevalent in the West where we tell the story that if you find yourself attracted to someone other than your spouse, it means you "made a mistake" about the spouse.
Naturally, people should be talking about that and making agreements at the beginning of getting together and ideally not in the middle of what they've agreed is an exclusive relationship, but until we accept that as a normal (and not fringe) option, it's probably going to keep going this way.
