Wondering about the cheating

I don't know why I spent so much time consumed in this. I was a good woman, and I catered to him like crazy. Nothing worked. Nothing I did was able to stop the cheating. I also wondered about the other woman. The first one I caught him with, well, actually, they were coming out of her apt. That didn't PROVE anything beyond the shadow of a doubt. But she was not what I would call a beauty. She was not skinny. So, what was it about her that made him want to be with her instead of me? Oh, I wanted to know the answers. I even asked him and all I got was pure denial of his infidelity. He was not guilty, so he said.