Me and Dan had been together around 5 years and had I active sex life. I thought all was good until I came home from work early and seen my friends car out side my house. This was not too unusual so I just parked down the street and walked back the house the door was open but nobody was down stairs. I walked to the top of the stairs and could see Dan fucking Sarah in our bed. I was fuming but found myself just stood watching and at one point even rubbed myself through my leggings. I could tell Dan was about to come so snuck out of the house and back to my car. I was sat waiting to see her car leave still feeling turned on by what I had seen . Her car past and I drove my car back to the front of our house and walked in. Dan was stood making a cup of tea and seemed shocked to see me early. I still don't know why I did not flip with him but instead I walked over pulled his shorts down and started to suck him. I could taste Sarah on him and this turned me on more after a few minutes he came in my mouth he looked down at me and said what's got into you. I could not tell him and just said it was it was invade he was asleep when I came back later after my night out. I headed up stairs to get ready and jumped in the shower I could not keep my hands of my pussy and had the most intense orgasm. I stepped out of the shower and picked out my underwear and cloths. I was sat putting my make-up on and was still turned on and that's when the idea came to me he had fucked some one so I would do the same that night. I got dressed and got Dan to drop me off in town but just before I got out of the car I opened my legs so he could see my knickers and said wait up for me if you want then I got out and met the girls. I got a text from Dan saying how much it had turned him on. We had a great night but all I could think about was getting even. I told the girls I was going for a fag but this was just a excuse to head off and look for some one and with in minutes I was chatting to a lads in his early 20s I asked if he wanted to head outside. We walked around the back of the club and after a little kissing I just asked if I could see his cock he smirked and opened his Jeans he was soft but I could not believe how fat it was. I got on my knees for the second time that day and started wanking him off I could feel him growing in my hands. He pulled my head towards his cock and I put has much as could in my mouth. He was ready for fucking and could not wait to feel him stretch me. He had to ease it in to start with but I was wet so it was not long before I could feel him sliding his full length in and out of me this sent me over the edge and I had a massive orgasm on this stranger's cock. He came within seconds of me and I could feel his cup fill me up. I pulled my knickers up thanked him and head home to Dan. When I walked in he was laid in his boxers I told him to take them of and i striped to my underwear and walked over to him. I told him to pull my knickers down and could see his cock start to grow. All I could think was you will not be smiling when you see what's in my knickers it's pay back. When he pulled them down the crotch was covered and my small triangle of pubic hair was a well. He asked what the fuck I had been up to but to my surprise his cock was still growing. I told him I had seen him fucking Sarah in our bed so I had evened things up and if he ever did it again so would I. His cock was now fully erect and he pulled me towards him and started playing with my pussy even though it was full of another man's cum. Dan the said he would let me watch him fuck her again if it turned me on this much and pulled me on to his cock. After riding him for a minute I told to get me from behind when I stood up I could see I had leaked the mans cum on his cock. He fucked me to me next orgasm then added his load to the stranger's. Since that night I've spied on him fucking Sarah and been out and picked men up so Dan can watch. But now we are looking for some one to join in with us. I can't wait.