My EXhusband cheated on me with someone who honestly looks just like me. We were both in the military, which made it very convenient for him. She was in the same unit he was in...I was not. From the first time I met her (before I knew that they were "more than friends"), I just didn't like her. That is weird for me, because I usually like 99% of the people I meet. She even came to our wedding! I was injured very badly during training, and was medically retired. He insisted that I return to KY to finish my Masters degree because he was getting ready to deploy to Iraq. Well, he was not so much interested in me finishing my Masters as he was in moving her into MY house. Anyway...I found out about it and all of the lies started falling apart. He admitted everything, and we divorced.
I didn't mention the fact that she is married to someone else, with children. I felt like calling her husband and telling him what was going on, but I didn't want to hurt him the way I had been hurt.
Sad thing is that if he told me today that he was sorry for what he did, I would take him back. You can't turn love off and on. It still hurts..probably always will.