Unbelievably I witnessed my wife firstly pleasuring herself , then secondly having full penatrative sex with a young man that came to stay at our house . Carl came to stop at ours just after Christmas this year, we had a garage conversion several years ago that our eldest claimed but since he moved out I used it to watch tv as there was a huge wall mounted tv and obviously a bed , it had its own toilet and shower area . One Saturday afternoon Sally mentioned that her Boss at work June had been talking that due to the building work on her house about to start she would encourage Carl her son to find some where to stop for a couple of weeks before he moved to Yorkshire to start a new job . Sally suggested that If I didn't mind he could stop at ours as it was only for a few weeks . I didn't mind as Carl was a pleasant chap , had a job etc etc . Anyway Carl moved In one Saturday, i was away for the weekend visiting relatives on that particular day . As I said Carl nice chap kept himself to himself, never noisy respectful of us all in the house . Well the first massive shock came about a week later , whilst at work I got a call from my sister saying mum's not well could i pop round to see her . On my way to mums I drove past our house only to see Sally's car in the drive , it wasn't unusual as the nature of her work ment she could regularly nip home . I pulled up got out intending to surprise her , i opened the outer porch door stepped in and at the same time looked through the little round window into the hall , i was about to open and walk in when I saw Sally standing by the door leading into the garage conversion. I couldn't believe it she was rubbing herself whilst looking through the crack in the door ! I could see her skirt pulled up and her hand was in her panties rubbing furiously! After a couple of seconds she walked into the kitchen straightening her self as she walked , totally shocked to be honest as you would be , i opened the door walked in shut the door and walked past where Sally was stud , the door was open slightly and as i peered in Carl was laying on the bed naked watching tv . I walked into the kitchen and Sally was making a cup of tea , looking shocked 'what are you doing home ? ' I explained about mum , bit of small talk and left . Couldn't get the fact she was masturbating whist spying on our guest ! So out of character as well. Over the next few days I noticed Sally change slightly, wearing more sexy clothing and basque and stockings made an appearance. Although I didn't benefit. One night in bed I mentioned that we will have to be quite as our guest might hear as Sally can be vocal during sex . Cricket she was so noisy Carl downstairs must have heard . Friday night I had arranged to go out , as i left the house I said to Sally behave yourself when I'm out . To which I was tolled don't be disgusting. I thought to myself I've seen you playing with your self , cheeky bitch . All night I kept in touch then at around 11.00ish I txt her saying I was stopping round Micks and i hoped she didn't mind . She messaged back stay safe don't drink too much. I had no intention of sleeping anywhere but at home . Around 12.30 I slipped away jumped into a taxi and headed home . I made the taxi drop me off close by and walked up the drive towards the house , i walked round the back , i had every intention of catching her up to no good . As I walked round the back I noticed that the blinds closed on the conservatory, we never close them ! I At the corner I could see into the conservatory where the blinds didn't meet properly, Sally was sitting drinking wine watching the television nothing unusual, after about 10 mins , she got up switched the lights off and walked through the kitchen switching the lights off as she went , i looked through the back door you could see right up the hallway . I just caught her turn and go upstairs. My mind working overtime thinking she's up to no good, totally wrong . I tried the back door locked , so as i turned to go back around to the front I noticed the hallway light come on and Sally appear , wearing bra and little panties , i knew it , as i watched she walked straight into Carl's room . In her panties !!! I darted around to the front and opened the porch door , this is always unlocked and we have a key hidden in the porch for the inner door. It must have been minutes since I saw,Sally enter his room , i unlocked the door and as i opened the door I could here that all to familiar sound , Sally obviously getting fucked ! To be honest i was totally turned on ,my wife having sex with a young man. I listened for a while but fear of getting caught as daft as it sounds I went back outside, couldn't believe it. I walked up the road not believing what had happened. I messaged Sally and said I was on my way home , as i sent it i knew she was sat on another's cock . I walked back to the house after about 10 mins making lots of noise, as i turned the key in the door Sally greeted me asking why I was home , i just said I needed my own bed as i had bad stomach , i went upstairs followed by Sally , i just kept thinking she's just been fucked . As I undressed and got into bed Sally asked if i needed anything I replied no , with that she took her dressing gown off , i noticed that she had little red silk panties on and not the white pair she had on half hour earlier , i tried it on but she was having none of it saying I was drunk ! I eventually fell asleep. Waking up in the morning at around 9.00 ish I was told by Sally that Carl was moving out today . Later that afternoon Carl walked into the conservatory where I was sitting , recovering after everything I had heard , he shook my hand thanking me for everything and left . I thought cheeky bastard . Months have passed and i haven't mentioned anything to Sally , we have had a lot of sex but i think that's because of her dirty little secret. Not sure if i tell her I heard everything.