I cannot believe that I am writing to a confession web site,but what I witnessed last week has left me completely stunned. I work away from home quite a lot and my wife Barbara runs the house and looks after our teenage children while I am away,anyway last week I returned home about 2.0pm parked my car in the drive and noticed a pick up truck belonging to the old man who does our garden parked on the drive,I looked round the garden,but couldn't see him so I let myself in and was surprised not to see Barb in the front room,then I heard voices from upstairs and quietly went up,our bedroom door was open and my wife of 25 years was stark naked on the bed,legs wide apart and Tom the gardener had his face between her legs and was obviously licking her pussy,Barb's eyes were shut and she had the familiar pinkness round her neck that she always got before she reached an orgasm,Tom was also naked and his bottom was pushing against the douvet as his tongue lapped at my wife's pussy.I know what I should have done,burst in and give him the beating of his life,but instead I moved so I couldn't be seen and carried on watching with a sick feeling in my stomach but also great excitement,my cock was stiffer than it has been in years then as Tom moved his head from between her legs and slowly moved up Barb's naked body I released my erection and slowly rubbed it.I felt as if I was in a dream as he positioned himself ready to fuck her then with one easy push I knew he was inside her,I couldn't see his cock but knew by the rhythmic movements he was fucking her and by the sounds Barb was making she was loving it.I watched for about 2 minutes then felt my spunk erupt from my cock onto the carpet,as soon as I had come the realization of what I was witnessing hit me and a feeling of jealousy flooded over me and I burst in shouting "what the fuck" Tom jumped up his big old erection quickly softening and started apologizing as he grabbed his clothes from the floor,he flinched as he passed me thinking I was going to hit him,but he is in his mid sixties and I didn't have the heart to.Barb was crying and saying how sorry she was and that she loved me and it would never happen again.Since then it has been very strained between us and she has been very contrite she told me the affair had been going on for about 6 months when I asked her why she said she had felt neglected and Tom had been good listener and one thing led to another,she obviously doesn't know i wanked as I watched them and that it turned me on so much to see her being fucked.I am now thinking of a way for me to join her and Tom in a threesome.Wish me luck