Ive been in this situation before though not exactly. What you should do is Run but hold your ground. You need to ask her how she feels about you, if she loves you enough then she shouldnt have to break up with you likee that. Also try viewing it from her point of view; maybe she feels bad for going out with someone who is ten years younger than her (sorry to say it like that) maybe she does LOVE her husband and wants to stay with him. Just be considerate of her feelings and hope that she is considerate of yours.

When I was 12 i was going out with a man who was 40 but didnt know it. We were interne chatting and I really was in looove with him, but his wife signed on in his screenname and when i said "hey babe" she cursed me out. So when i asked his friend (who was 19) he said "that he was 40 and married with 5 kids" I was so angry that i apologized to the wife. She kicked him out and he got arrested and while all of this happened my mom still didnt find out...

Just take it slow. See what happens but dont be negative towards her if the outcome is bad.