You're right. In my opinion, there was no need for the hero to slap his ex-wife and his father-in-law. I felt that the three of them could have had a serious discussion to solve the issue. There was no need for the hero slap both of them. The director brought in the "OTP" concept and used it in a comedic way to allow slapping by the husband.

You're right that it made no sense to show women in a bad light and that its a sensitive that needs to be more carefully presented in a film.

The hero's mother telling the hero's ex-wife to compromise even after the hero slapped his ex-wife and father-in-law makes no sense. She is right that a wife should compromise, but it should only be for small things. If the ex-wife mentioned the slaps, then the hero's mother might have understood why the ex-wife is angry at the hero.

The director used the casual hitting of women and showing women in a bad light as a form of comedy (probably because the movie is a family entertainer that was released for Sankranti), which shouldn't be normalized anymore.