I have been reliving this memory in private for the last 2 weeks it's only fair that I share.

So I work as an electrician and couple weeks ago I was working on a switchboard at the local university. It was late afternoon and I still had a few hours to go. I thought I'd put in the overtime with Xmas coming up it could be useful. The switchboard is in a small room just off one of the offices, at about 6pm I heard the security guard come past and lock up I made myself scarce so I could keep working. I carried on and about an hour later I heard the front door open and two women whispering and giggling. They called out "anyone here??" I kept quiet because I wanted to be able to work the extra hours without being sent home.
I heard them getting glasses from the kitchen and assumed they were just sneaking some of their social clubs wine. Pretty soon I was suspicious that they were upto something else. I could hear heavy breathing and groans. My mind was racing and my cock swelling I had to go check it out.

I snuck out from where I was and crept down the hall to the lunchroom where the sound was coming from. I carefully poked my head around the corner and there they were two women in their late forties one rather large and one pretty fit looking. The fit one had her head buried in the large ladies pussy while she laid back with her blouse unbottoned and her massive tits hanging out. I watched this and jerked myself off for about ten minutes. When she came she began to sit up so I fear of being seen I quickly crept back up the hallway. "Now it's your turn" I heard one of them say. I listened from down the hall as the fit one was getting undressed. I couldn't take it anymore I was so horny by now I started walking back down the hallway but this time not sneaking purposefully being loud. I heard them trying to get decent as I got closer. When I got in the room the big lady still had her tits out and the other one had pulled her skirt back Down but her panties were still arournd her ankles. "Who are you??" They asked. "The electrican I said I'm working here. Long story short I ended up joining in. We had all sorts of kinky sex for the next 2 hrs including me cumming in the fat ones ass. I put my overtime sheet in the next day and paid for the best sex of my life.