Wifes mother

I am male and 28 now.
I am married to a wonderful woman I met at my first job out of college. We've been married for 4 years now. But here's the funny thing. Her mom doesn't remember, but when I was 17 I fucked her. She had been drinking and was in a parking lot trying to find her car. I was with some friends and she was in no state to drive so we offered to help her and drive her home. I drove her home, and when we got there she told us to come in for a drink. Long story short, all four of us took turns fucking her. She took total control and we left her fucked, dripping cum from her brunette haired pussy, her asshole, and cum all over her face and incredible tits and she loved every second of it. She was so out of it she doesn't remember it was me, but I remember.