I've no idea what affect horse riding has on most women, but in the case of Jenny, my wife, beside the pleasure of being on horseback, a couple of hours in the saddle makes her frisky. After riding was the only time she instigated sex, even then it was strictly missionary. She liked sex, but it was unadventurous. Blow job? Forget it. Outdoor sex, even somewhere there was no risk of being seen? No chance. Keeping a horse is not cheap, but we both worked, Jenny mainly to pay for Henry her Cob. When her hours were reduced, we had to cut back. I suggested selling Henry, not a chance. “I'll do anything to keep him” she told me. One of the cars went instead, we didn't really need two anyway. Her work was in town, the stables about a mile away within walking distance, if she needed the car I could always catch the train. The arrangement worked fine, though with her hours cut she had little money left after paying the cost of keeping the horse. Her hours were reduced again, I mentioned the cost of keeping Henry and she told me she'd come to an arrangement with the stable yard owner, to pay less and give him a hand on the yard. Often she'd come home after riding and go straight in the shower, instead of dragging me of for a shag. I didn't really give it any thought, thinking that perhaps it was the worry of paying for Henry, though on the up side she did seem a bit more adventurous, asking me to do her doggy. Only with hindsight did I realise the significance. It was a Monday last June, I'd gone to work, it was quiet, I was owed some flexi and took the afternoon off. Jenny had the car to take some things to the stables, so I caught the midday train and was home by 12.30. The house was empty Jenny up the stables. Being Monday the riding school closed, the staffs day off, though people who stabled their horses were able to go. But with most people working it was unusual to see anyone but Tony the owner. I changed and decided that as it was a nice day I'd wander up to the yard, and watch her riding. A 15 minute stroll along a bridleway, hedges each side hiding my approach, brought me out close to the barn,. Both doors were open, hay and straw bales piled up, a ladder giving access to storage space above. I could see through the barn to the stables and yard beyond. I couldn't see Jenny, but could hear her, laughing and shouting at someone to stop spraying her with water. Usual yard antics, messing about with the water hose on a hot day I assumed, entering the barn. I’d taken 3 or 4 paces towards the opposite doors when Jenny ran into view closely followed by Tony. They were outside in bright sunlight, inside the barn it was dark so even had they looked I wouldn't have been visible. I suppose you could call it messing about, except Jenny was topless, her 40dd tits swaying and bouncing as she tried to escape from Tony. I say escape but she wasn't trying to hard as he caught her, grabbing her tits. The tits she was so self conscious about she refused to wear a bikini on holiday. I'd tried persuading her, told her that her 40-25-36 figure looked fantastic, but to no avail. Now here she was cavorting, half naked. I was torn between confronting them or watching to see what would happen. I imagine you've guessed the choice I made. I, like many men, have fantasised seeing another man with my wife, but knowing what a prude she was had never dared ask. I wondered how far she would go with him. I wanted to find out, looking around for somewhere to hide and watch. The ladder to the loft was next to me, that seemed the best bet. I went up as quietly as I could and crept over to a loading door, above the yard. It was open a few inches, enough to see what was going on. I could hear Jenny shrieking with laughter, as I found a position to watch. Tony still had hold of her tits. He had pulled the top of Jenny's Jodhpurs open and shoved the hose down the front. She was wriggling attempting to dislodge it while he held it pushing it between her legs. It rapidly got to the point when she was soaked and he pulled the hose out. She was still laughing, Tony was pulling her big rubbery nipples, telling her how suckable they looked as he slipped a hand inside her jodhpurs rubbing her pussy. Things were hotting up and my prick was almost erect. Would my twenty six year old wife let Tony, who's about fifty, fuck her? It looked as if I was about to discover the answer. I again thought of going back out of the barn and making a noisy arrival, give them time to stop. I was torn between wanting her to stop and watching her possibly being fucked. I didn't move, except to open the door an inch or two wider watching him finger Jenny, my decision made. I wanted her to let him fuck her. She'd just started rubbing her bum against him when I heard a vehicle coming up the driveway. They also heard it and she quickly grabbed her top and put it on, and began grooming Henry. I recognised, the other man, Gerard who owned one of the other horses. He came into the yard, carrying a saddle, greeted them both then went in to the Tack Room. That's stopped any chance of me seeing her shagged I thought, wondering whether to leave. I was getting ready to go when I heard Tony and Gerard in the the barn bringing stuff in so I was trapped for the moment, sitting waiting for them to go. I could hear them talking, Jenny's name being mentioned. I didn't catch everything but the gist was that Tony had been fucking Jenny in part payment for Henry's stabling. I strained to hear more, listening as he described how she'd bartered her pussy for Henry's upkeep. They went to fetch something from the car, still talking about her when they returned. I caught enough to realise that he wasn't the only one fucking her for favours. Gerard called him a lucky bastard, making a comment about her tits.“Do you want to see them? I'll tell her to get'em out” he paused a moment before continuing. “Hang on. I've got a better idea, I'll tell you what. I owe you a favour for this stuff. She owes me a fuck. You can fuck her if you want.” he told him. “Won't she mind you giving her away?” Gerard asked. “No, she loves cock. She was a bit frigid at first, until Frank, the Farrier fucked her. Now she's a real dirty slut. Any time, any place, any hole” he laughed, “Do you want to have her?” Gerard responded with an enthusiastic “Yes” They went out to Jenny. Tony lifted her top, giving her tits a squeeze, inviting Gerard to have a feel. She just let them, even tweaking her nipples erect asking if they wanted to suck them for her. Tony let go of her tit and said “We were thinking more along the lines of fuck not suck. I've told Gerard he can fuck you” She didn't look remotely shocked or reluctant, answering “Fine with me. I don't mind which of you fucks me. That reminds me, Frank might pop in if he's passing. I still owe him three fucks for the half set of shoes last week” Henry whinnied at the sound of her voice. “I hope you appreciate what I'm doing for you Henry” she laughed, already pulling her top off, her heavy tits, swinging as she threw it over a stable door. Tony told Gerard he better get a move on, warning him that if Frank turned up and fucked her first, her cunt would be so stretched he might as well shag an empty bucket. Jenny sat on the mounting block, pulled her boots off, then her jodhpurs and panties, sitting back naked, her legs parted, displaying her pussy. She'd started shaving two or three months previously, “I fancied a change” she'd said, more likely because she'd been told to. From twenty or thirty feet I could see her pussy, already looking wet enough to fuck. My prick was hard, straining inside my jeans, I adjusted it, but was still uncomfortable, and unzipped releasing my cock, holding it in my hand wanking. Gerard was still undressing, Jenny reached down touching her pussy, running a finger along her slit. She opened her legs wider, her cunt lips parted more, pink hole shining with sex juices, pushing two fingers in and out of her pussy. I realised she was masturbating. I'd tried to persuade her to wank or use a vibrator while I watched, she'd claimed to be to embarrassed to play with herself with me there. My cock seemed to get even harder, watching as she openly masturbated in front of Tony and Gerard, seemingly unembarrassed, smiling and clearly enjoying herself. Gerard was down to his boxers, he moved closer to Jenny, she continued masturbating reaching with her other hand, gripping the waistband, pulling his boxers down. His cock sprang out, about 7 inches and thick, looking impressively hard for a bloke pushing sixty. She pulled him closer, pushing his boxers right down, leaning forward to lick his shaft. Holding his cock steady she licked around the helmet, then up to the tip, lapping the liquid seeping from the eye. She parted her lips, her hand moving, as she stroked his prick. She took it in to her mouth, wanking his cock as she began sucking him off. Another thing she'd always claimed not to like and here she was sucking him like an expert cocksucker. She looked like she'd had lots of practise. Up and down her head went, taking him right into her mouth, her cheeks bulging as he fucked her face. For three or four minutes she gave him head, her fingers flashing in and out of her cunt as she wanked and sucked. He didn't seem close to cumming, I was and had to stop stroking my prick. He said something, she stopped sucking, before standing, turning around and bending over, legs spread, hands resting on the aptly named mounting block. He slid his prick between her legs, rubbing it along her slit. “Don't bother doing that. Just put it in and fuck me” she called out, raising herself, using her fingers to guide his cock into her hole. I held my breath, my hand barely moving on my cock, watching as another man penetrated my wife’s tight little cunt. His prick slipped smoothly inside her receptive pussy. He reached for her tits, cupping them, pinching her erect nipples as he fucked her. I could see Jenny's arm moving, obviously rubbing her pussy. I could hear her sighing as Gerard began fucking her, giving her long steady strokes, penetrating her deeply. He started fucking her faster and harder, I could hear their bodies slapping together, then Jenny panting, nearing climax, crying out that she was cumming, not the usual, quiet whimper, but loudly, almost screaming. To much for me I shot my wad, unlike Gerard who continued fucking her. She was like a rag doll, throwing her head from side to side, her body shuddering as he kept thrusting in and out of her cunt, shafting her, to a second orgasm, slamming his cock in her, almost lifting her off her feet, as he finally ejaculated inside her, pulling out and shooting a couple of jets on her bum. He moved back, thanking her, picking up his clothes dressing, chatting to Tony as he walked back to his car leaving Jenny, bent over, still getting her breath, spunk slowly trickling down her buttocks, dribbling from her cunt, running down her legs and dripping to the ground. I would have loved to have gone down and fucked her or licked her out I was so excited by what I'd witnessed. I didn't dare, needed time to think, decide what to do. I'd already decided one thing though I didn't want her to stop. I heard Gerard's car start and drive off, Tony returning, talking on his mobile, Jenny had stood and was wiping her pussy on a rag. I tidied myself listening as he told Jenny it had been Frank on the phone, saying he wouldn't be popping in. I'd forgotten about him and I'm not sure who was more disappointed, me or Jenny, that he wasn't going to drop by and fuck her. I heard her asking Tony if he wanted to fuck her and him say he was already late for an appointment and didn't have time. I don't suppose he was missing out on anything as it seemed he was fucking her whenever he liked. He went off towards the house leaving her to get dressed and giving me the chance to leave without being seen. I walked briskly back to our house to await Jenny's return. I already had some ideas but wanted to think and plan before deciding what to do and say. I knew one thing, she was prepared to whore herself for Henry. What else would she do?