I was being sent on a two day training course for work. I packed my stuff and kissed my girlfriend Tegan goodbye and hit the road. I was soon there and sat in a classroom learning about the new equipment. It was the first time that they ran this course. On the first day we covered 90% of the material, which meant that the following day we would get away much earlier than expected. I tried to ring Tegan to let her know, but I got no reply. I thought it would be a nice surprise for her anyway. We finished by ten thirty and was quickly back on the road. As I pulled into my road I noticed a car I didn't recognize on my drive. I just coasted straight by and stopped in the adjacent road and walked back. I let myself in quietly by the back door. I could hear loud music and crept up the stairs towards the music. At the top of the stairs I could see Tegan in bed with someone else. I crouched hiding and could see Tegan on top moving her hips. She was fucking someone. I considered rushing in and beating the bastard, then it dawned on me that he might be bigger and stronger than me and it might be me getting the beating. I heard Tegan groan and then roll off her lover. The lover was moving and that's when I first saw who it was. It wasn't another man it was Faith, one of her girl friends. My girlfriend was having a lesbian affair. I slipped quietly back out of the house and went back to my car. I didn't know what to make of it. My girlfriend who had never displayed any signs of being a lesbian was having a lesbian affair. I was hurt, confused and a more than little excited. I needed to think this through. I drove to a pub and sat with a beer thinking about it. The excitement was greater than the other feelings and I decided to go and confront them. By the time I got back there the car and Faith were gone and Tegan was hoovering the lounge. I started to doubt what I had witnessed. Tegan seem genuinely pleased to see me home early. She was due to go out with friends that evening and after she went out I started to look for signs of her infidelity. I searched the bedroom and came up short. I looked around the lounge and again there was nothing to see. Then I looked in the waste bin. Just a few inches down the rubbish I found a condom. There was still traces of cum in it. Then I found another and another until I had found seven in total. Either he was a stallion or there was more than one and you don't need condoms for two girls. When Tegan got home she was more than a little tipsy and I challenged her about the condoms. Tegan giggled and said, "don't be silly one man wouldn't use that many there was four of them." I was shocked and shouted at her, "You slept with four men." "No silly," she replied only two of them Faith slept with the other two. It suddenly dawned on her that she might now be in trouble for what she just confessed to, and she was sobering up fast. I demanded to know who they were. Tegan suddenly realized she was in real deep trouble and went quiet. I again demanded to know who they were. Tegan quietly told me she had no idea. They had come with Faith and after quite a lot to drink she found herself in our bed with two of the men. After they had their way with her they left as did the two with Faith. Faith then joined Tegan in bed. She returned the following day and that was when I saw the pair of them in bed again. By this time I had one hell of a hard on. I grabbed hold of Tegan and bent her over the sofa pulled her panties down and fucked her silly. It was only afterwards did I regret it when I remembered the reason she would have insisted on condoms was that she was not on the pill. We had a long worrying wait for her period to begin. Fortunately begin it did. Four weeks later I was due to be going on another course and Tegan already knew the dates. Unbeknown to Tegan I had changed the dates. I dropped my bags at a mates house who said I could stay for two nights. and sneaked back to the house. From my garden shed I could see Faith arrive and they were hugging and kissing. Not just the kiss of a mate, but those of a lover. It must have been nearly two hours when yet another car arrived and out got four men. They were a good ten years older than either Tegan or Faith. I watched as the four men took their cocks out and Tegan and Faith worked their way around all four sucking them. I moved closer to the side of the house next to the slightly open window. They were divvying up who was going to fuck who. Three of the men wanted to swap on who they fucked the last time. The last one insisted that he liked Tegan and wanted to fuck her again. He lost out. It was now with their cocks still out of their pants, and looking hard as hell, they dragged both women up the stairs. I tried the back door and it was unlocked. Stood at the foot of the stairs I heard Tegan insisting, "No condom, no fuck." At lest she had insisted on safety. A few moments later I heard a loud groan from Tegan. Although I wasn't in a position to watch I knew that it was the sound Tegan makes when I penetrate her. It was quickly followed by Faith moaning. Then there seemed to be an endless moan and groan from the two of them. I heard a few hurry up, I want a turn. Then it went quiet for a few moments and then it started all over again. I guessed that the number two's were now fucking the pair of them. Twenty minutes later it went all quiet again. I stayed listening for about five minutes and was about to retreat to my shed when Tegan gave out a long loud moan. Someone was fucking her again. It wasn't too much later when Faith was also groaning. At this point I couldn't take any more and retreated. Having wanked in my shed with the noises swirling around in my head, I settled back down and watched. It was nearly an hour before the men came down stairs. Both Tegan and Faith were with them and still naked. The men each groped both girls and kissing them. Then they left. Tegan and Faith went back up stairs. I could only guess what they were doing. Whatever it was in reality it had me hard again and wanking. Afterwards I returned to my mates house. The following evening I returned to my shed. Tegan and Faith were already naked and kissing. The door bell rang and Faith went to the front door still naked. Two of the men from the previous evening had also returned. This time I didn't have to imagine as they both stripped and donned condoms. From my shed I could see everything. There seemed to be some joking around and then the taller one laid my wife on the sofa and climbed between her legs. I watched as his cock slowly but firmly slipped deep into her pussy. Then he was fucking Tegan for all he was worth. The other man sat in an arm chair and Faith impaled herself on the mans cock. After they finished and rested it started again. The men donned fresh condoms and this time the tall one bent Faith over the arm of the chair and started to fuck her from behind. The other man then had Tegan also bent over on the sofa and plowed her pussy. I was stood there with the hardest erection of my life. The men finished with the girls and dressed more kisses, hugs and gropes, then they left. the girls were then going up stairs. I gave them ten minutes then let myself in and sneaked upstairs. Faith was on the top and they were kissing I could see them rubbing their used pussies together. Before either of them knew what was happening I had stripped and was behind Faith and slammed my hard cock straight up Faiths wet pussy. I could see the shock on Tegan's face and hear the moans coming from Faiths mouth. I came deep inside her and then realized that I had forgotten the condoms that were in my trouser pockets. Fortunately Faith was on the pill. I spent the rest of the night in bed with both girls sucking and fucking till the early hours. That evening and night triggered many nights with the girls fucking other men and me sharing them afterwards. Whilst Faith eventually married and moved away. Tegan continued her naughty ways with my blessing. We discovered that Faith and her husband were following our example and two years ago they were home visiting her parents and we got together for a foursome. Things of course have ground to a halt at the moment, but when we get back to normal Tegan and Faith want to arrange a holiday together. I'm looking forward to that.