Some years ago, around the early 1980's, I worked occasionally away from home, and had been asked to cover for a colleague at the far side of the country in Norfolk. This meant I had to stay over as it was a near 4 hour drive from home. The colleague I was covering for had a bit of an issue with his wife, leading eventually to divorce a year or so later. Simon and I had become friendly, as I was the only other branch manager willing to go over and cover for him during this stressful time for him. So when he left the family, and was relocated quite close to us, it was natural that we started to socialise more and also that he came to stay over some weekends. On one of these weekends we had decided to go for a game of squash. The centre we used had several courts and a bar, as well as a sauna that could be booked for exclusive use. Knowing the facilities there, my wife decided to come with us with the intention of a drink or two, and a session in the sauna. After the game, Simon and I went into the sauna with my wife. I don't know what he was expecting, but as naturists we had no qualms about getting naked and settling in for a nice relaxing time. Now at this point, you may want to know that Simon and my wife got on very well, with quite a lot of flirting a regular thing. With both of us naked, Simon felt he needed to follow suit. As you will know, a sauna is great, but it does mean you need to shower frequently during the session and we all took it in turns to pop out of the cabin to use the shower. On one of these refresh events, (it was a large shower area) he was showering when Sheila said "I think I might join him" We're not innocents, had had threesomes and more over the years, so I had no worries about this, and besides, I could watch discretely as the sauna cabin was unlit! Sheila left the sauna for the shower, and walked in behind him then turned on the second shower head. He realised someone was in the cubicle with him, and turned to see Sheila there. Being quite forward, she asked him to soap her back, and he happily did this. Sheila returned the compliment for him, but being a cheeky little minx, reached round to soap his balls and cock. Fair to say, this was a surprise for him! Instantly hard, he looked over to the sauna to see if I had noticed, but he couldn't see me in there. Thinking I didn't know, he soaped and fondled Sheila's tits and down her stomach to her pubic area - which incidentally is always kept very well trimmed - and gently inserted a finger or two into her cunt. Enjoying this, she let him continue for a few minutes, at the same time wanking him gently, becoming more rapid as she sensed he wouldn't let too long. Though Sheila didn't come at this time, Simon had a violent response, spraying his cum all over Sheila's hand, arm and body. As a result, she needed to wash again, and Simon stayed in the cubicle for a while waiting for his erection to subside. A few minutes later, Sheila came back into the sauna, while Simon stayed out for a few more moments. She told me what she had done, though I had seen it all anyway. Hearing us talking, Simon came in and tried to apologise but was astounded when I said there was nothing to be sorry for, Sheila knew what she was doing and anyway, we loved each other enough to do what we liked, with who we liked, whenever we liked! I think he was relieved! I said it was perhaps time to leave for home - he was staying with us for the weekend - so had a quick shower myself while they dried off and dressed. There was no embarrassment on out part, though Simon was still a little subdued as we went home. Later, after the kids were in bed, we had had a few drinks, and I put a porn video on, this was several scenarios but primarily threesomes. I still think Simon was unsure about the situation, perhaps thinking I may have bi or gay tendencies and therefore had designs on his body! Realising Sheila wanted to take things further, I said I was off to bed, leaving them alone on the sofa with booze and porn available. Knowing I could both observe and listen, I made a reasonable amount of noise going up stairs, thinking I would wait until I could hear some activity. In actuality, Sheila came up behind me, and stripped off in the bedroom. I asked what she planned, and in answer she put on barely black hold-ups and a lace basque - nothing else at all, gorgeous, sexy woman! She went back downstairs, and I clearly heard a gasp from Simon as she walked in the room. Some mumbled conversation for a few minutes, then it went quiet except for the porn on the TV. I gave it a further few minutes until I heard a gasp from Sheila, then crept quietly down to the dining room, where I could peer into the living room without being seen. Sheila was sitting alongside Simon and had her legs wide open, tits and fanny on display, as Simon sucked on one nipple and had a hand playing with her clittoris. Her gasps, and her busy hands undressing him, were all accessible to me without interrupting their activities. She quickly get him naked, and for the first time I realised he had quite a good cock. It was about the same length as mine, slightly slimmer but was circumcised, unlike mine. Sheila went down on his cock, taking it all in her mouth in one go, then pulled off it completely as she walked him a little more. This continued for a few more minutes, whilst she was being brought very close to an orgasm, then she pulled away from him and lay down on the sofa, legs wide apart. She asked him to lick her cunt while she frigged her clit, and within a few minutes came to a shattering orgasm. Her body went into convulsions, then slumped into limp and happy state. Simon moved off her, and stood looking down at her seriously sexy size 8 body. It took some minutes before Sheila came back to reality, then said to Simon "You've not cum yet, and I want you to fuck me now" so without hesitation, Simon got settled between her legs, and I could see him entering her cunt for the first time. Fabulous sight! Bare arse bouncing over her, he thrust slowly at first, savouring the feel of her hot, tight wet cunt around his dick. Speeding up the thrusts, he brought Sheila to another climax within 3 minutes and then came himself as his buttocks clenched and his seed was shot into her vagina, as they were fucking with no condoms. Clearly spent, he pulled out of Sheila, who dripped some of his cum onto the sofa before she got up and used some tissues wo wipe herself clean, before cleaning Simon's cock with her mouth and tongue. She said she needed to go to bed - Simon used to sleep on that same sofa - so I hurried up the stairs and into our bedroom as she came up herself. Knowing I would be awake, Sheila asked if I had seen or heard all that had gone on, and I said yes to both. "Oh good. You'll be ready to fuck me too" she said, and to be fair, we did indeed enjoy a fast and intense fuck in the following minutes. I always cum more quickly immediately after Sheila has played with someone new, but in this case, Sheila was face down as I entered her, then we shuffled position so that she had her legs together and mine were outside hers, as we both prefer this to any other position. Brilliant time that night, but it didn't end there. I woke up about 03:00 to find she was not in bed. I went downstairs, and this time walked into the living room to find Sheila lying on the sofa with Simon busy fucking her again. "Oh shit" he said. "Don't mind me, you two carry on, you know I have no problems with this, don't you?" I left them to it, but had made it clear to Simon that I had no issues with him fucking Sheila, it was entirely her choice and more importantly, her pleasure. Over the next two years, she fucked Simon on many occasions, but we never did manage to get it into a threesome.