In my situation he turned on me to save his own hide. When his wife found out he told her that I wouldn't leave him alone, that I kept calling him etc. etc. It was quite the opposite, all through the relationship I would always bring up not seeing each other any more because of the quilt I felt of him having a family.
So it was easy for me to let go of the relationship because the hurt of loosing him (or at least what I thought I had) quickly turned to anger because of his betrayal.