@polishknight I hope this last bit of the year is going well for you too.
And I honestly understand your point of view; I wouldn't even say you're wrong. The only thing that impedes me of agreeing with you is believing that such secret will eventually come to light, and then the whole relationship will come crashing down - prompting the guy to make the decision of staying or leaving either way. But then he'll be older, more settled in his ways, and maybe even with kids.
Nevertheless, we only get to hear about the cheatings that did come to light; we'll never know about the successful stories. So, I can't disagree with you either.