Wrong reaction. You don't stay because of something you want to hear. You stay because she has proven herself to you. You are going to say that she did by being honest, etc. But let's face it, she wasn't. You had to drag the truth out from her.
At that point, you should have asked her "why"? Something like "why would you want me to stay?" "I need to feel that you are someone I can trust and you haven't been open about things. Why should I believe you now?" And then let her respond. Her answer would have given you an idea of how she would make things right.
"It was the sting of her saying I had my own part in the A."
I can't stress this enough...NEVER EVER TAKE THE BLAME OR HAVE SOMEONE BLAME YOU FOR THEIR OWN AFFAIR! There are other, healthier ways of dealing with issues in a M. But an Affair is the most selfish thing another person could do. It breaks all kinds of boundaries and is not justifiable by any means. Don't ever have someone pin the blame on you.
M-43 W-40 2D - 9 and 5
Emotion, yet peace. Ignorance, yet knowledge. Passion, yet serenity. Chaos, yet harmony. Death, yet a new life.