There are many reasons couples drift apart and break up, but one of the most devastating might be cancer. According to one study, men are six times more likely than women to leave their wives after their partner gets a cancer diagnosis. But not all men leave; some choose to stay and cheat.
Like this guy, who was unfaithful to his wife during her chemo treatment. Her best friend took care of her during that hard time instead, and grew to loathe the husband. So, when he became a widower and asked her to babysit the kids so he can have more free time with his girlfriend, the woman blatantly refused.