The generational cheating does seem like an interesting coincidence By the way, my husband's sister cheated on her first husband. One thing I've noticed is they seem to easily dismiss the behavior as due to unhappiness in the marriage (as if that excuse makes it okay).
But I felt really sad, discouraged, unloved and unhappy in my marriage at times. There was a time I felt like nothing I ever did was good enough for my husband and this really pulled my self-confidence down.... and yet I never felt the desire to have an affair. It's just not something I'd ever do. The opportunities have been there, but I could never act on something like that because it would feel really uncomfortable for me. I truly can't imagine how it could ever feel good. I just don't understand.
Even through my own parents did divorce (over my father's alcohol and anger issues), there were never any affairs on either side. My mother never did remarry but she did date one man for many years. She never lived with anyone. She believed that was inappropriate (and this is a woman who was a stunningly beautiful bathing suit model in New York when she was in her late teens/early 20s. Seeing her you wouldn't have expected her to have morals).
There is no arriving, ever. It is all a continual becoming.