Well, not my own relationship. But there is the same exact problem I noticed that happened to three of my girlfriends relationships and I'm curious as to thoughts on why this phenomenon happens.
Basically, my friends contributed a lot to their relationships and in essence feel like they've "made their boyfriend/husband into the man that he is now" (meaning career). And all their partners ended up cheating on them, and now my girlfriends feel resentful because "he wouldn't be the man he is without me and then he has the nerve to have an affair."
One example is my friend used to be a career woman in finance, and she basically advised her husband in economic growth because he was climbing the ladder to become CEO level. He achieved his goal, then he had an affair and she's extremely resentful because she feels his success is due to her. Also she had supported him with her high salary while he was studying his MBA (now she's a SAHM living on his salary).
I'm sure there's more to it (perhaps there was some shrew attitudes knowing all three of these girlfriends are a bit aggressive) but this seems to be a recurring problem.
Are these cases of domineering women trying to mold their men? Lack of respect? Too much control? Not letting him "earn you" and giving too much? Too much advising and not enough listening?
Wouldn't a man who chose a women who made him into a better man, cherish her? Why did these men have affairs if his woman supported him and his successes?