My husband and I met in 1997. We got married in 1999. He wasn't seeing anyone when we met and I had recently dumped my cheating ex fiancé. The relationship WAS over despite my ex continuing to protest my moving on and stalking me for the next year. Once we got engaged, the ex finally gave up. The point is, we didn't cheat to be together. We've never cheated on one another. I don't think it will ever happen.
However, my sister met her husband while still married to her ex and he was married as well. 20 years later she still constantly worries about him cheating on her. Paranoia, is how I would describe it. She says all women feel this way but I know I don't. Our other sister doesn't either. Don't you think it is the fashion in which they met that causes that??