Do people not understand that this is a comedy series? Sure, comedy can be a way to address a serious topic without excess drama, but I think some people are expecting too much. If there is a point the mangaka is making, it’s not that cheaters should always be condemned and punished.
I’m going to say what is probably going to be a hot take for a lot of people in this comment section, if someone cheats, something has already gone very wrong with the relationship, and all the flags up to and including now pointed to the husband being the problem.
The biggest clue was what someone else mentioned a few comments ago. Long distance will put a strain on even the best of relationships, so extra effort is highly advisable. Mizuki went above and beyond to deliver home-made meals for months when there are delivery services that could do that for you, and her lame duck husband needed to be reminded by his own daughter to exercise the basic human courtesy of saying “thank you”? Not good enough! I say ”thank you” to the random stranger who holds a door open for me! Mizuki is a treasure and she should be showered with affection for the extra effort she personally put in.
”Oh, but he obviously works hard to provide for his family”. That alone is not good enough. People have needs beyond the financial. That’s no different from saying a parent should get a pass for neglecting a child simply because they pay for everything. Evidence points to the fact that Mizuki’s emotional and sexual needs have not been met, which is incidentally one of the most basic motivations for cheating. It goes without saying that if you don’t meet the needs of your partner, they’ll eventually look elsewhere, with or without your approval. Frankly, I’m surprised this woman lasted as long as she did.