For the record, nothing I said is incompatible with what you’re saying. Something can both be the result of a wrongdoer’s blameworthy choice and the consequence

For the record, nothing I said is incompatible with what you’re saying. Something can both be the result of a wrongdoer’s blameworthy choice and the consequence of social structure. People don’t have a problem understanding crime in general that way, but for some reason the suggestion that sexual misconduct might have to do with changes in sexual norms is met is treated differently. E.g., there are ways of organizing our society that would make murders much more common. Suggesting that we not organize our society like that does that does not entail the suggestion that the murderers, who wouldn’t murder if the society were organized differently, wouldn’t be responsible for their actions. And yes, the world is full of people who have been left by a partner for no good reason other than the grass being greener on the other side, including, as just one example, women being left for younger women. There are some well-known instances of this in public life right now. When there is a stronger norm of lifelong monogamy, I think people are more likely to internalize their commitment and stick it out, just like they internalize other norms of rightful conduct. There are, allegedly, fairy tale marriages out there, but most of the older folks I know who have had successful, lifelong marriages will tell you that it wasn’t always easy or what they desired at every moment, but that at various points they stuck it out for the kids, out of obligation, out of love (the commitment, not the feeling).