Hypothetical cheating situation

I know most of us are completely against cheating and would leave immediately if we were cheated on, however, I was having an interesting conversation with a client (probably in her 50's or 60's) the other day and she told me her husband of 36 years was cheating on her and she had accepted it. She wasn't planning on leaving, she wasn't staying for the kids as they're all adults, there was no real reason other for her to stay but she had no intention of leaving. In fact, she's on welfare and she would more than likely be better off if she left seeing as they pay more to singles.
So my question is, do you think you'll ever get to a point in your life where cheating becomes something you just accept/live with?
It's anonymous because I want it to be. Every time I post you guys go out of your way to attack me for asking regular non offensive questions And the cheating wasn't a one time thing, he openly has a mistress.