Your example showcases a relationship that is perfect in all aspects other than sexual. Many relationships are not that. In many relationships emotions may go s

Your example showcases a relationship that is perfect in all aspects other than sexual. Many relationships are not that. In many relationships emotions may go sour, trust may fade, etc. before sex becomes dysfunctional (think about the existence of makeup sex), all while both partners choose to remain in the relationship for entirely rational reasons. And as time passes, making the choice of divorce becomes harder and harder. But indeed, the topic of is so very nuanced even in cases like the example. From an outside viewpoint, there theoretically might be better alternatives but people are complicated. A divorce, at least in the short term, is a lose-lose proposition, except: - cases where either one is in a life threatening situation (most usually women due to domestic violence - a death-lose situation) - cases where the law allows one to have net gains at the expense of the other and do so repeatedly (in this case marriage and divorce become a wealth transfer strategy - a win-lose situation) In the above example, theoretically, transitioning to an open relationship would be a better alternative, allowing both partners to compartmentalize the dysfunctional parts of the relationship. But this solution is not always plausible. Proposing such a solution is not plausible in many cases. Even pondering such a solution may not be plausible in many situations. Because, in many cases, simply having it known, that such an idea was given though, is enough to unravel relationships. See all the comments that vilify "emotional cheating".