Cheaters Beware

You are a 43 year old man who has spent most of his life in the fast lane. 9 years you have been seeing Amy. Living together but for a little over a year of separation. At least 4 women have made you go astray during this relationship and now she suspects there is another. One more hurtful and damaging than the rest. Your best friend's wife. He has been your friend for over 20 years, she was your side chick back in the day before she started going with him. Overall, they have been your friends for over a decade. Are you cheating on your girlfriend with her? Have you been having and off and on again affair with her for the whole relationship of her and your best friend?