How i got to fuck [m]y moms mature [f]riend.

This all dates back about 30 years. I was 18, living with my parents in a rural part of Germany. Small town, everybody knows each other.
My mom is close friends with a woman who runs a small boutique. Let’s call her Mary.
I have always had the hots for her. Shes is 40 years old at the time, slim, big breasts and always dressed sharp and feminine. Trophy wife to Ben, the local MD. Many a night masturbated to various fantasies involving her.
Fast forward to new years day. Mary and her husband Ben are throwing a new year’s party in their big house. She invited a lot of people over. Her husband and her hired me to attend the wardrobe. There is about 150 guests, i take their coats, hand them a note with a number and hang the coats over the huge handrail of a mezzanine in their house. I also collect glasses and keep people’s drinks filled.
The party lasts until 4am. Mary and her husband put a foldable bed in their office room for me to crash on as i have also agreed to help clean up after the party tje next day.
Mary and Ben have gone to sleep. I had hoped to get lucky to hear them fucking, Mary was wearing a tight “fuck me” dress all night and i caught myself looking at her more than i’d like to admit.
No luck though, they are sleeping tight. I brush my teeth in a small guest bathroom and go to my room. I am trying to sleep, but the bed is uncomfortable and i am restless.
I decide to switch on the small color TV in the study to help me get tired. However, it’s not helping. Under the TV there’s a VHS recorder. There some tapes lying around, mostly copies if some 80s movies. One casette is special, it’s one of those adapter casettes for the small tapes that went into old camcorders. There’s a cabinet with a stained glass door, and i can spot some of these tapes.
Curiosity gets the best of me, i take one of the tapes and put it in the VHS machine. The image comes to life and i can’t believe my eyes. It’s Ben and Mary, fucking in bed.
I mute the volume, it was already silent before. I can’t believe it. Here is Mary, her big tits bouncing, riding Bens cock with her pussy which has a nicely trimmed black bush.
The next five hours are spent monitoring every tape around. Many of them are normal stuff, birthdays, holidays. But five tapes are filled with nothing but them having sex.
I watched them all, stroking my rock hard cock all the time. Finally, i make myself cum, store all tapes nicely back how they were and drop into bead, dead tired.
The next day, after a very short night, i help them clean the house. Tired. Very tired. Also i can’t forget her body, now that i know what she looks like in great detail, i have a constant boner. In the next years, every time she comes over to see my mum, i have blue balls. I want her, badly.