On the 31 Oct I posted a story about when Mary and I had rented a villa and for the only time had sex with other partners. She read the story and was a bit quiet after and I thought I'd upset her. That night we made love and she then told that the end of the story was wrong. Rather than nothing similar happening since she had been getting a regular shagging after attending the Gym. As she described what had happened I got an erection and she knew that instead of being angry I was excited by the thought of her allowing other men to fuck her. She is now 43, has large firm tits and since she started going to the Gym has lost some weight, is curvy and looks good. She was being fucked by two of the instructors and a number of men who would stay behind when the centre closed. She liked having all these different cocks shafting her but said she would stop if I wanted her to. I told that far from wanting her to stop I wanted to join the Gym and find a way to watch and participate. I jog and keep fairly fit so I went to the Gym the next night. I exercised and chatted to her as an instructor gave advice. I moved away and watched as she did some exercises with the instructor and could see him slipping his hand up her shorts and touching her pussy. I left them to it and got changed before going up to a viewing area above. They were alone and from above I could see he had his hand down her shorts and was fingering her as she stroked his cock. It was almost closing time and one of the instructors was checking every one had left, came to say it was time to go. He could see I was watching and laughed when he said "Oh, that's Mary, she's a real dirty slut, do anything. I expect she'll be getting a good seeing to before she leaves". He then showed me out and locked the doors. Mary got home about an hour and half later, she'd showered and washed all the spunk from her cunt but as we fucked she told me that the instructors had said I'd seen her being fingered. She told them she had spoken to me, thought I was nice and that if I was there again, she wanted to invite me to stay on. We both went a couple of nights later and made the pretence of hardly knowing each other and I went through some exercises with her with the instructors help. It was almost time to close and most people had gone except two instructors, me another man and Mary. I still wasn't sure if anything would happen, until the building was locked, and we went to shower, Mary included. We were all naked and Mary was being washed, groped and fingered by four pairs of hands. She came before we even left the showers and we all had erections. We picked her up by her arms and legs, carrying her to some mats where she lay spreadeagled, her cunt open and wet. Two of us were sucking her nipples which were harder than I'd ever seen as she had her clit licked, sucked and nibbled while the fourth was over head having his balls sucked and licked. She was groaning and writhing on the mat as an orgasm coursed through her. She stopped sucking his balls and asked him to fetch a rounders bat. We all watched as he slowly inserted the thick end into her cunt. She was so wet that it easily penetrated her stretching her wide as she took about 9", before he started to slowly withdraw it until just the last inch was in her. One of us was rubbing her clit, as the bat was pushed back in she was arching her back, lifting her arse up for a better entry position gasping "Fuck me with it faster". The bat was slick as it was moved faster and deeper into to her cunt until, after several minutes, shaking with lust as she came. The instructor was right when he'd said she was a total slut, who'd do anything, she was behaving like a tart, a tramp, a whore and I loved it. The bat was put to one side and she was pulled down the mat and onto a waiting prick. Despite the bat fucking, she was ready for more and moved in time with him rising to meet his thrusts as he porked her. She was on the boil and was soon shouting for him to cum in her as his sperm unloaded inside her. She was covered in perspiration, as she got on all fours, sweat was running down her tits and, as they swayed, dripping from her nipples. She was entered from behind and I positioned myself by her mouth and lifted her head by her hair as I pushed my cock to her lips. As she was fucked she opened her mouth and closed her lips tightly round my prick and sucked. She was being pushed from behind and each time my cock slipped deeper into her mouth until she was forced to swallow me and I moved in time, fucking her mouth, her red lips holding me tight. A few more thrusts and I came in the back of her throat. The other man carried on fucking her for another minute until he came in her cunt. The final bloke had been watching us and stroking his prick which was long but quite thin. The instructors had gone to dress ready to leave as it was getting late. Mary reached for his cock and pulled him to her mouth and slowly sucked it for a couple of minutes still on all fours. He reached over her back and when I moved could see he had pushed a finger into her bum and was moving it in and out. She slipped his prick from her mouth and said "Take your finger out. I want your cock in my arse". This was something we'd never done, although I'd fancied trying but never asked, as I wondered how many times she'd been fucked in her arse. He pushed his prick in her cunt first then using his fingers and saliva lubricated her puckered hole. She was fingering her clit as he spread the cheeks of her bum wide. The tip of his cock was against her arsehole and slowly and gently he opened her up with his cock. Her arse ring stretched open and his prick entered her. The instructors rejoined us and we watched as she was arse fucked, him spitting on her, to keep her well lubricated as he fucked her hard, his balls slapping against her cunt as he banged her. She was shouting, telling him to spunk in her arse, she came as he carried on fucking her until he suddenly stopped as he pumped his semen in to her. Mary was laid on the mat cum and pussy juices running from her cunt and spunk bubbles from her arse. She lay there recovering as we got dressed and fetched her track suit. It was late and we were let out, she kissed everyone and said she was looking forward to the next session before we left in separate cars. Once home I told her how much I loved her and how horny it had been watching her getting fucked. I wish she'd told me sooner that she had wanted more cock. She said that after that holiday she'd often thought of how nice it would be to try different cocks and when the opportunity arose she couldn't stop. When I showed her the story in SH she realised that I would welcome the chance to see her being fucked again and to join in. Since the first time, I have watched her receive multiple fuckings twice and so far she has been shagged by seven different men, none of whom know that Mary is my wife, which adds to the thrill when they talk about what a slut she is and speculate whether her husband suspects anything.