I guess she felt better off with the other person. I guessed the 3rd party did not even know of my existence. Things just happened and love is something unpredictable. No one knows what will happen in the end. I had, but things did not work out the way I wanted it to.
Scars can never heal.
Some mistakes done cannot be undone. I might, depending on how deep my love for her was at that point in time. But, of course, I would become more wary. Do unto others what you want others to do unto you. We have to be realistic.