A plot could also be that the husband has a hidden family. He has a wife and kids in another location but has created a new life with another woman, presenting himself as a perfect bachelor. Eventually, the truth comes out, and the woman who thought she was with a perfect husband realizes she has been deceived.
One possible plot could be that the husband is having an affair at work. He acts all loving and perfect at home, but during work hours, he's involved with a colleague. His wife might start to suspect when she notices changes in his behavior, like being more distant or getting calls at odd hours.