At what point do you break up a couple?

Usually for the same reason a couple would break up/divorce in real life, for example when one spouse cheats on the other with someone else (either autonomously or with my "help") or if they just constantly fight and I don't know why. It could also simply be for storytelling purposes.

I find it funny how people here write things like they feel "guilt" or feel sad afterwards, it's still a game after all.