It's case by case basis.
To be honest, I'm more and more looking at relationships from a financial perspective first, and then we can get into the emotions of it. If it's financially beneficial for you to stay with someone who cheats, particularly if it was a one-time thing and not an ongoing side relationship, and you don't have another more viable, realistic alternative, then
That advice goes more for women than men in theory, but works both ways really. I've never been in the actual situation though, so I don't know how I'd actually react.
Financial foundation for affairs of the heart is not the way to go. Seems trendy today, but most people are a natural disaster or nationwide catastrophe from money being useless.
You gotta be able to ask yourself "if the world blew up today and I had to survive off the land, would I want to be with this woman?"