More Than a Carpet Cleaning

My wife and I are in our late 30's and have been happily married for ten years. Although our sex life is great, I have always had a fantasy about watching my wife have sex with another man. Last summer, we moved into a new house and decided to have our carpets cleaned before unloading our goods. We called one of the locally owned establishments and they said they would send someone out the next day.
We were busy unpacking boxes the next day when we saw the cleaning truck pull into the drive. Out came a man of about 30 who was tanned and obviously hit the gym on a regular basis. Right away I noticed my wife checking out his snug fitting shorts. I continued on with my work and my wife Debbie showed him into the house. For the next hour he was busily cleaning the carpets while she was frequently going back and forth to 'see how he was doing'. She obviously was hot for him and he took more than a few glances at her hard nipples pointing from her shirt.
In a semi-joking manner I asked her if she wanted to have sex with him before he left; maybe he'd give us a discount. She jokingly replied it certainly would be worth a try. I could tell in her eyes, however, she was wishing she could. I figured what the hell, this opportunity may never come by again so I told her to go ahead. She looked at me and with a nasty smile said 'you're serious aren't you?'. I said yes, but only if I could watch.
We worked out a plan where I went into the master bedroom and sat in the closet behind the shuttered doors. When it was time for payment she would have him come back to the bedroom and at that point make her move. A short time later I heard the door open an could clearly see Debbie and Ken standing side by side. As she reached for her checkbook she pretended to fall and she fell to her knees in front of him. With a wry smile she said 'the view from here sure looks good; mind if I take a peek inside'. With that, she pulled down his shorts. You could see a bulge forming in his tight undershorts. Debbie rubbed it from the outside for a while and it appeared to be getting quite large. She pulled down his shorts and I think she nearly came on the spot. His cock was easily eight inches with a massive girth. She started sucking it like she had never seen a dick in her life. Meanwhile, I was watching from the closet, my cock throbbing. It was only a minute before Ken started writhing and moaning and she pulled his cock out and squeezed it to keep him from coming.
'I'm not going to let you finish until you put that inside me' Debbie said. 'Why don't you take care and taste some of this for a while'. She then laid on the bed, her open vagina looking at me. Ken ate her for several minutes until Debbie yelled for him to stick his cock in her. She moved to the side so I could see Ken jammming his huge cock in her. Meanwhile I was in the closet shooting off the most intense load I've ever experienced. They both soon came and collapsed in the heat. Ken dressed and left shortly and Debbie gave him a deep kiss before he left the door. When she got back, she laid on the bed and told me to come out. I opened her legs and could see a large gob of semen dripping from her pussy. I slowly licked around it and then drove my tounge deep into her box. Never has her pussy tasted so good. We ended up spending the rest of the afternoon having unbelievable sex.
Now, about once per month Debbie has Ken over to clean one of the rooms in the house. He agreed to let her tape some of their sessions so if I can't make it home to see it live I can watch it with her later.