I rent a small serviced office close to my home. There are 10 offices here, but some of them are unoccupied due to the recession. There is a communal kitchen area where from time to time I get to chat with the other occupants. On the whole though it is very quiet and very private, which is how I like it. A few months ago one of the guys (Mick, a recruitment consultant) took on some extra resource, Jenny one day a week on a Wednesday. Jenny is in her late 20s I guess, Mick late 30s. Mostly on Wednesdays Jenny is there on her own and keeps herself pretty much to herself. I have spoken with her now and then, and found her a little flirty and sexy but there certainly hadn’t been any decent banter. Sometimes the two of them work in Mick’s small office together on a Wednesday. This must be quite claustrophobic. I tend to leave the office early on a Wednesday so that my wife can go out. I’m rarely there after 6pm. However about a month ago my wife couldn’t go out as I had a meeting in London. The meeting ran into the evening, finishing with a few beers. I got on the train and popped into the office to collect my laptop. It was about 7.30 in the evening. As I came into the office I was surprised to see that the lights were still on. I took a look around to see who was still in. As I peered into Mick’s office through the small window in the door I was shocked to see that Mick had Jenny up on the desk, her skirt was hitched up around her waist, his trousers were around his ankles and he was banging away at her. Mick had his back towards the door and I could see Jenny’s face over his shoulder, but she had her eyes closed, obviously in ecstasy. I watched for a while, feeling my growing cock through my trousers. Mick was beginning to thrust into her faster and they were both making animal noises. At that point she opened her eyes and looked right at me. She just smiled and winked at me before closing her eyes as he emptied his balls into her. That was my leave. I knew that Jenny had seen me but Mick hadn’t. I've met Mick's wife so I thought I’d leave it up to him to come and talk to me about it another day if he felt needed to. Jenny had other ideas, but I’ll leave that till part 2.