God knows why but I thought I'd get this off my chest.
So basically, when I was about fifteen, I came home early from school as sport training had been cancelled. The door was unlocked and so I just went into the house but as I got into the hallway I heard noises coming from upstairs. It sounded like moaning.
I went up the stairs very quietly and saw that the noises were coming from my parents room. I couldn't believe what I saw.
It was my mother getting fucked by a guy in the year above me at school. I'd never seen sex before but I realised looking back on it that she was certainly cumming as they had sex. Eventually I heard him ask her where she "wanted him to finish" and she replied "inside me". I watched as a boy in my school ejaculated inside my cheating mother on my parents' bed, and then when they looked finished and like they would be getting up and dressed I quickly but quietly went back downstairs and back out, coming home later when I was expected to be home.

Later on that evening, I was doing my homework in my room even though I could hardly think about anything except what I'd seen earlier that day, and my mother came in. She began by making small talk about school etc but it was obvious she wanted to talk about something. She sat on my bed close to me and told me that she knew I was watching earlier.
I didn't say anything. I had no idea what on earth to think or say. She said to me "You aren't going to tell your father, are you?". I just shook my head. She seemed pleased with that, and stood up to leave, but as she got to my door, she turned and asked me "Did you... enjoy watching it? Enjoy watching me?".
I looked at the floor and didn't answer until she asked me a second time. I told her the truth, which was yes.

She closed my bedroom door, turning the lock and walked back to me, knelt down, and asked if I'd like her to do something nice for me. I asked her what she meant, my heart kind of thumping at this point.
She told me to sit facing her and to take down my shorts. I nervously did so, and she pulled down my boxers revealing my penis. She made me sit down, and then proceeded to take my penis in her mouth. My first ever blowjob came from my mother.
She kept going until I came, and she swallowed it all. When she'd finished, she smiled at me and just said "Our little secret, ok?". I nodded.

I watched her with boys whenever I could (some were from my school, some weren't), her always making sure she left the door open so I could see but keeping the boys facing away so they wouldn't see me watching.
And she would always reward me later that day with a blowjob for my silence.

This all ended when I left for college, coming home rarely after that. As far as I know my dad never knew what she was up to. I realise it's a pretty fucked up way to grow up and it was horrible in some ways but fucking exciting in others.