I’m not sure what it was that made me realise I was turned on at the thought of my girlfriend with another guy. I’m guessing anyone reading this knows what I mean. It’s not the usual thing. Part of it is the fact that I think my girlfriend is stunning. Everyone finds their partners attractive, and everyone likes different things. For me, my girlfriend is perfect physically. Tall, brunette, curvy, with long legs, and an attractive face she’s got the lot that I look for. At first I used to try and detach myself during sex. You know, watch her reactions, her face as she came. But it was difficult, because I was involved, in the middle of it. So, I bought her a vibrator, pretending it was for her, but really, knowing it was for me, so I could see her, gasping, as she came. And, for a while, it did the trick. But, eventually, I wanted to see a cock inside of her. I picked the moment, and suggested videos, threesomes, and even an ‘open relationship’ but she never bit. I pretty much gave up, and consigned the image to fantasy and that was that. We’d been together for three years, when I first caught wind she was cheating. Just a couple of suspicious comments, unexplained late nights after night classes, and a good friendship with a music student she knew. We weren’t living together then, but stayed with each other most nights, and both had keys to each others places. One night, a Thursday, we were both out with different groups, in different parts of town, and agreed we’d just catch up the next day. This wasn’t unusual, but something in her tone immediately set my heart fluttering, and, having sunk a fair few vodkas, I drunkenly decided to wait outside the club she was in, and keep an eye on her. She lived a five minute walk from the club, and, after wandering past her house and seeing no lights on, I wandered up to a secluded spot outside the club, and, I’m ashamed to admit it, waited to spy on her. At quarter to two she emerged. Clearly tipsy, she looked stunning. A knee length tight black leather skirt covered her immaculate legs, and she wore black knee high boots. She was wearing a tight, red top which accentuated her 36DD breasts perfectly. When I saw her I was filled with pride, but seconds later, my heart sank, as the long haired music student she’d become friendly with, exited the club, and walked over to her. For maybe 30 seconds, they talked, and she gave an almost imperceptible nod. My heart sank again, but my cock leapt, as they began walking towards her house. He lived in the opposite direction. He had no reason to go that way. Unless…. I waited a couple of minutes, no clue what to do. My hands went to my pockets, to find a cigarette, and closed around the keys to her ground floor apartment. From that moment, the course of action was set. When I arrived at her address, the lights were on. I waited, a long long time - maybe 40 minutes - for them to go out, and he didn’t emerge. God knows what they were doing during that time but, once the lights were out, quiet as a mouse, I let myself in. I was in luck. The low hum of music was coming from her bedroom, which gave me some cover, instantly. As I made my way towards her bedroom door, my second piece of luck became apparent. She hadn’t locked her bedroom door, and as such, there was no key in the lock. I bent down to look through the keyhole, and the fantasy I had carried for so long, was realised. The first thing I saw, was them lying on her bed, fully clothed, mouths entwined. His hands were eager, running over her body, and she was lost in the moment. This carried on for a few minutes, before she sat up smiled at him, and climbed astride him. Running her fingers down his chest, she kissed his neck, and face, before moving her head down. Rather clumsily, he removed his shirt and she kissed his naked chest, expertly teasing his nipples with her tongue. She continued lower. Reaching his beltline, and, whilst trailing her tongue across his stomach, she unzipped his trousers and slid his hand inside. He threw his head back as she worked his cock free of his jeans, and whilst she ran the nails of one hand down his chest, the other slowly worked the shaft of his cock. She said something to him, I don’t know what, because the music was playing. But a few seconds later, she hovered an inch or two above the tip of his cock, and flicked out a tongue. The first contact was brief, the second and third also, the third was more precise, running across the glistening head of his cock. Still, he strained against her, trying to push it into her mouth, but she continued at her own pace, completely in control, teasing her with his tongue. Finally she took him in her mouth, and he moaned loudly, loud enough for me to hear it above the music. Julie gives great head. I mean, really good. I’m fussy about blow jobs, but there’s something she does with her tongue when your cock is in her mouth, that sends you wild, and this was no exception. Literally 30, or 40 seconds in, I saw his body go tense, and Julies hand stop working his shaft as he pumped into her mouth. Shaking with exhileration, adrenalin, jealousy, and lust, I backed away from the door. I walked down the hall to her front door, but, something held me back. I don’t know what. But I didn’t leave. After hearing no movement from her room, after 5 minutes, I crept back, and took up position at the keyhole again. He may have come quickly, but he was standing to attention again, and stood by the side of the bed, removing his trousers. Julie’s skirt and knickers had been removed, as well as her top, so she was naked except her boots, and lacy bra. He was reaching into his trousers, and withdrew a condom, and began to unwrap it, but she pushed his hand away. He climbed onto her, and rubbed the tip of his cock against her wet slit, his turn to tease. She wrapped her legs around him, to try and pull him into her, but he held back, letting his fat head slip in, then withdrawing. Finally, after what seemed like ages, he sunk in fully, thrusting into her, sending her crazy, building up a slow rhythm. His stamina had clearly been boosted by the blow job he’d received, and, they went through a good reportoire - him on top, her on top, doggy, side by side, paused midway for oral, before carrying on, and I watched every minute, taking in the view of her face in the ecstasy a human only gets during sex. I’d wanted to see it for so long, I was mesmerised. If I’m honest, I must have come three times during that 40 minutes, and she certainly did at least twice. He was back on top at the end, and was rougher now, thrusting into her hard, trying to work to orgasm himself, and his moment began to arrive. He began to pull out of her, but again, she wrapped her legs, still in their boots, around his back and pulled him in deep, her long, dark red nails digging into his back. He gave one long thrust, and came, twitching as he filled her with his come. It was the most erotic thing I’d ever seen. I slunk away, minutes later, disgusted with myself, and her. For a couple of days, I fought with it, wondering whether to confront her. On the Saturday, she went out again, and I followed the routine, but this time, was caught out, spotted outside the club, and her cover was blown. She admitted they’d kissed but nothing else. I kept the truth to myself, but since then (5 years on now), she’s either been faithful, or much, much more careful. I’ve had a couple of suspicions, but nothing concrete. As the memory of that incident slowly fades with time, its become more of a fantasy again. Once again, I’m longing for a man to seduce my girlfriend. If theres a man out there, who thinks he’s up to the job, and is willing to be part of this fantasy, with a beautiful 28 year old girl, please let me know. Believe me, you wont regret it…..