The former guys constantly asked her to put a title on the relationship: boyfriend/girlfriend, dating exclusively, or what? This habit of looking for titles made the guys appear insecure and also made my friend feel trapped.
She couldn't take the relationships seriously.
My friend admitted her reasoning was not a good excuse to cheat, but she rationalized it by telling herself she cheated because she felt trapped.
But she changed when she met her husband. Somehow he was able to allow her space, and he wasn't always demanding answers about their relationship. The cheating stopped and they lived happily ever after.