it all started a few months ago my wife katie started going to the gym we had a pretty good sex life but after a while i thought there was something up, she used to come in after the gym go to bed and wait for me then wanted sex. now going from 2 to 3 times a week to 5 or 6 and then in the mornings as well at first i thought it was all the workouts doing the trick until one evening i picked her up she was late so i went in to see if she was ready there were a few guys still there on the running machines i could see katie through the mirrors on the stepping machine so i just waited in the passage way i went into the male dressing rooms for the toilet as i was there the door opened and a couple of guys came in they were talking and as they went into the showers i heard them saying wish i could give that bird one as katie was the only one in the gym it had to be her they were saying her fanny lips were blowing kisses when she was on the bike and laughing i walked back into the passage way and looked in again i could see this younger guy holding her hips as she stepped looking at her arse as she was working out they were chatting away about her body he said you have a nice bum she said it was to wobbly he said i think i could firm it up she laughed and as she started to come off i went and stood on the stairs, she went off to shower the younger guy who now i know is one of the trainers there went into the mens locker room the other two guys were asking him about katie he said yeah she's fit and wouldn't mind giving her one just then katie came out and saw me i said i've just been to the toilet and off home we went later that night as we were fucking i said i herd them talking about her she shrugged it off but after a while started asking questions about who said what, i asked her if she fancied any of them she said they were to young we are 40 and they are about 25 / 27'ish. after another few weeks she started to get later and later she said it was her routine taking longer to do, she knew i was'nt jealous as it's been a fantisy of mine for someone else to fuck her for years, the previous weekend we were out drinking when we got back i took some pics of her in different positions etc, i said to her take them in and leave them on top of your gym bag she said i cant do that incase some body else picks them up, i said wait until you go into the shower and shout for barry to get you some towels as they just put them in on the benches as they cant see into the showers i said i bet he has a look. the next evening she did but was nervous about doing it she could see barry putting the towels down and looking at the pics lying on top of her bag they wer upside down so he took them and had a look as he turned them over she could see his face light up he took one out and started to rub his cock as she started to make a noise he put it back and went out. she said she was nervous as she was leaving barry said katie could i ask you to stay back a bit i need to go over your workout with you, she said ok i'll just ring my hubby to say i'll be late as she rang me i knew what was going to happen all i said was enjoy yourself, she was in her jogging pants & sweat shirt with no bra on. he was sitting on the gym bike talking to her she could see the bulge in his shorts and let the pics fall out onto the floor as she picked them up he said let me lok at those she said no there private pics he laughed and said go on she handed them over, she said she felt horny and could see his cock bulging as he looked at them, he quickly said i think it's time for me to firm your wobbly bits dont you before she could answer he was kissing her he then said wait there went down and locked the door came back up and without a word stripped off she said she cum as he had a great body and was hairless all over he then lifted her top off and started to suck her tits before she knew it her bottoms were on the floor stepping out of them he took her there and then standing lifting her leg up he thrust his hadr cock up her she cum again they lay on the floor and he fucked her twice straight off cuming in her and then shagged her arse they have been shagging for a while now and i caught her sending pics of herself to someone off her phone to another guy at the gym