Had a friend who's wife started assuming he was cheating or trying to cheat with any other woman in his life. It was very extreme. Like - he once held the door open for a random woman entering a restaurant and she started accusing the woman of being a whore.

He ended up staying with her for a few more years because their daughter was 16 and he didn't want to end up paying child support, and when they split up the 18yo daughter moved in with him.