Hi, this is a first time story about a first time experience which happened last weekend. Those expecting expecting exploits of large scale group sex had better pass on by, but it is a true story of our first encounter. I'm Paul and my girlfriend is Jan, we have been going out for about seven months. I'm 49 and she is 50 so neither of us is in the first flush of youth but we have an active sex life, in fact we went to bed on our first date which was a bit of a surprise for both of us. She is blonde, 5ft 4, size 12 with a 38D chest. I'm 5ft 10 average build all over. We had planned a weekend away in Brighton for my birthday and thought we would take in a trip to a naturist spa located up near the marina as a bit of a treat. The web site said it had rest rooms although the reviews indicated they were for anything but resting. After a nice day of wandering round the lanes, taking in the gay pride parade (very colourful) and a very leisurely lunch in the marina, we made our way to the spa about 5pm. Having paid and gone through the door, we found outselves immediately in the changing room. We both stripped off quickly and grabbing our towels waited to be shown round. In the basement were various saunas, steam rooms, plunge pools and jacuzzis - all done out in a roman style. Next floor was a chill out area and the rest rooms were above that. It was couples only after 5.30 so there still quite a few single guys around as we went back down to the basement. We did the rounds of the facilities. It felt a bit strange wandering around naked at first but then we forgot about it. The club had a rule of no amourous behaviour as they put it in the basement. That didn't stop me sucking on Jan's nipples while we were alone in the sauna. After sampling everything we decided to go up and grab a drink. We noticed more couples coming in and decided to go back down. It was certainly more crowded this time, but we still found we had the steam room to ourselves and Jan gave me a quick suck on my cock which got me erect very quickly, but had to stop as someone else entered. We chatted to a few couples in passing, it was strange to think that if things went further we might do more than just look at their naked bodies. We eventually decided to go to the next step and wrapping towels round us went upstairs. The rest area had a number of single play rooms and three larger ones. As we went in there were two couples in the first room, both women were giving blow jobs to their respective partners, well I assume they were their partners. We watched for a bit and then wandered round to the largest room where two guys were giving oily massages to two women. Both were on their backs, one guy was ensuring his fingers were brushing his partners pussy every time his hands stroked up her legs. Jan was rubbing my cock through the towel and whispered "Shall we go find somewhere?". We found the remaining larger room free, it was covered with mirrors - wherever we looked we saw ourselves reflected many times. We spread our towels out and laid down and start to kiss and stroke each other. It was very tender. It then became more intimate as she slipped down and took my cock in her mouth. This is something I have learnt she is very good at and she loves licking up my pre cum. As I lay back I could see a guy reflected in the mirrors standing at the room entrance. He was wanking himself slowly as he watched us. Jan then slid back up my body transferring her hand to where her lips had just been. In return I slipped a finger into her very wet pussy. She started to squirm and groan then kissed me deeply. As we both increased the speed of our hands, the guy at the door had moved further in to the room. The pace of his wanking seemed to have increased to match ours. All three of us were were getting audibly louder and then we all seemed to come at the same time. The guy picked up his towel and left. Jan licked my cum off her fingers. We just lay there stroking each other, a little bit surprised at what had happened. We were still there about 10 minutes later and I was getting hard again when a couple entered the room. They were about our age. He dropped his towel and his partner began to stroke his cock. This carried on for a few minutes and Jan whispered shall we ask them to join us. I nodded not sure what to expect. They came forward, he was lying between Jan and his partner and I was to Jan's right. The guys left hand started to caress Jan's leg. I took my finger out of her pussy and put it in her mouth and let her suck her juices off it. My hand returned to her boob, as it did she gasped as the guy's finger slid into her pussy. He was now fingering both of them. This turned me on even more. We adjusted positions so that we all kneeling facing in like a diamond shape. Jan asked if they were one of couples massaging each other. They said yes and would we like some of their oils. They shared it out and I started to rub some into the other woman's very erect nipples. They very much larger than Jan's and I was dying to suck on them. Jan still had hold of my cock and was rubbing it gently. I bent my head to suck on the large nipples and felt the hand on my cock loosen and then grip again. I looked down and realised that the two women had swopped cocks. Jan was now rubbing the other guy while he kissed her and rubbed her tits. My hand slipped down to the other woman's pussy and went straight in - we started to kiss as well. We had now fully swopped over. We carried on for a few minutes and then the other couple got up, said thank you and picked up their towels and went out. We never got their names. My head was still spinning as we grabbed our towels and followed them out. We stopped at the first play room were the two original couples had now progressed. One couple was doing it doggie style - the other was with the woman on top. I could see the guy's cock slipping in and out. It was the first time I had ever seen someone else having sex. I was still hard and said to Jan "I have to fuck you now". "Good" she replied and grabbed my hand, we went into one of the single rooms. She dropped her towel,bent over and I slid straight in. I didn't last long and filled her with one of the longest cums I have ever had. After that we left to shower and dress. We realised we had been in there for over three hours. Over dinner we discussed what happened and said we would like to do it again and possibly go further next time. That night in the hotel she dressed up in stockings and suspenders and we relived the afternoon several times. Looking forward to our next adventure and would appreciate any recommendations on similar clubs in London and South East