Old friend from school tells me something i didn't know

Meet up with my best friend from childhood and we end up swapping secrets

Met up with my best friend from over 30 years ago. He moved away after leaving school, and he got in touch when Facebook started. We chatted occasionally over time and he came home on Saturday to see me. We went for a few beers, and as quite often happens with men, talk got around to sex and relationships.
We are both single and I said with looking after my dad before he died I haven't been with anyone for a while. He said the same as his sister had committed suicide. Then he asked if I wanted to know a secret he has kept since before he moved away. But wasn't sure how I'd take it if I did.
I'm easy going and said yeah, go ahead. He told me that one night after he had been to my house he went home a bit earlier than normal as he had homework to do for school the following day. When he arrived he was just about to go in through the patio doors, and stopped as he saw a man and woman on the dining table. He was fucking her, and he stood and watched for a few seconds before he realised who they were. It was his dad and my mum.
He said I watched them until they finished and then sat in the garage until your mum left. I never knew if I should say anything to you. So I've kept quiet until now.
I always wanted to fuck my mum, so it didn't bother me to hear this, in fact it turned me on a lot.
I told him I knew she had a lot of affairs but I didn't know she and your dad had one.
Then said I got a secret too. They used to live in a dorma bungalow and his bedroom was downstairs, but when I stayed over he slept in his sisters room and I stayed in his. I said One night your mum and dad had friends over Anita and Rob. I woke up around midnight and was thirsty so went to the kitchen to get a drink. As soon as I opened the door I heard moaning. I looked through the crack in the living room door and I could see his dads arse. I went closer and could see more. He was fucking Anita. Her legs wrapped around his back. Behind them Rob was fucking your mum. So am guessing they must have all been swingers.
We laughed about us keeping the same sort of secrets all these years.
I didn't tell him any more info than what I've just said.
But I watched them for about half an hour
His dad hammered away at Anita. I could see and hear his balls slapping her arse with every thrust. He turned her over and fucked her doggy style. He pussy covered by a mass of ginger pubes. Rob was stoo, with Carol sat on the sofa sucking his cock. I'd always fancied Carol. She was wearing a a black suspender belt and brown stockings. I was desperate to see her pussy but couldn't as she was sat with her legs together. She must have been good at sucking his cock because he was clearly loving every second of it.
Chris had stopped fucking Anita and they both went over to the sofa. He got Anita to lie on her back and told Carol to do the same. They both lay legs in the air as both men entered each others wife. I got my first look at Carol's pussy. It was bald. I yanked at my cock as I had never seen a bald pussy before. Robs cock was long and thin and he took long slow strokes. Anita legs were wrapped around Chris's back. I now saw she was wearing black hold up stockings.
I was pulling at my teenage cock and shot my own load all over the floor. I panicked like fuck. Ran to the bedroom and grabbed my socks. And used them to wipe it up off the tiles.
I went back to watching and Chris and Rob had swapped and were now fucking their own wives.
It went on for a few minutes and then both men stood up as the ladies sucked them. Chris said something I didn't hear, and Rob stood aside, he wanked his cock and shot his load all over the faces of Carol and Anita. Then Rob wanked his cock and told Carol to suck him. She put her mouth round it and within seconds Rob was moaning loudly. Anita had taken his full load in her mouth and she kissed Carol. I saw Anita spit some of robs cum Into her mouth. I went to bed and wanked my young cock again. Shot my second load Into the already cummy sock.
When I got home the following day I emptied my bag and mum took my dirty washing to the washing machine. She asked what was on my cock. Embarassed to fuck, I lied and said I spilled some drink and mopped it up using the sock. Great memories from all this years ago