Me and my girlfriend's relationship is pretty much your average relationship except for one thing: my girlfriend fucks other men. I don't like it, but my girlfriend has repeatedly let me know that if I even try to tell her who she can or can't sleep with, she won't think twice about leaving me. I know she has fucked her exes as well as random guys, but I don't know many details besides that. She doesn't feel like telling me, she says. However, I've found used condoms, hickeys and on one occasion even had to suffer through a night of hearing her moans while fucking another man. However, I was lucky enough to never have had to see her give herself sexually to another man. Until recently.

A close friend of mine told me his cousin was getting married, and invited me to the wedding. I had never met my friend's cousin, but I had known my friend for years, so I accepted the offer. My friend also suggested I invite my girlfriend. Later that evening, I called her and told her about the wedding, and she agreed to accompany me. The wedding was a couple of weeks away, so I had time to get my suit dry cleaned, and to take my girlfriend to buy a dress for the wedding. She looked beautiful in the dress, but it was nowhere near the short, revealing dresses she looked so hot and nasty in when she was partying.

The day of the wedding came, and it was great. My friend's cousin was a cheerful, friendly young woman, and I was genuinely happy to see her get married with an attractive man she repeatedly claimed was her soul mate. The wedding was a large one, packed with people. My friend told me after the wedding, the reception would be held at the banquet hall, and after that a smaller party would be held at his house with only family, but I was more than welcome to be there. Having no plans, I agreed.

After the wedding, I told my girlfriend that my friend had invited us to the small gathering being held at his house. My friend told us to change into something more comfortable for the gathering at his house, giving me the chance to enjoy watching my girlfriend change from her dress into a pair of tight jeans and a low-cut top. When we arrived, I noticed that only the bride's family and the groom was present. My friend explained that the groom's family had to leave earlier to catch their flight back home. My friend was quite a drinker, and I could now see it was a family trait, as everyone was getting hammered. I spent much of the night sober, dragging people to beds, couches and wherever else I could lay them after they had passed out.

After finishing dragging my friend to his room so he could sleep, I came downstairs to find my girlfriend sitting one of the few couches that wasn't being used as a bed, drinking her beer and talking to the groom. The bride had passed out earlier, and her new husband was taking full advantage to flirt with my girlfriend, making her laugh and laying his hand on her thigh. I decided to crash their little party and sit on the couch between them. My girlfriend sweetly smiled at me, asking me if I had a cigarette because she was dying for one. I gave her a confused look, seeing as she knew I didn't smoke. The groom answered that he did, and she invited him outside the house for a smoke, since she knew my friend hated the smell of cigarettes and always made people go outside to smoke. She suggested that, since I didn't smoke, I should stay inside and watch after everyone who had too much to drink. Not wanting to cause a scene, I agreed and let them go.

Suspicious, I headed towards the second floor of the house and opened the window, right above where my girlfriend and the groom were standing, and poked my head out. My girlfriend and this man were indeed smoking cigarettes, but I wasn't sure I could trust either of them and continued to spy on them. Since I was using the second floor window, I couldn't hear their conversation; I only had a bird's-eye view of them. So you could imagine my surprise when my girlfriend put her cigarette out, dropped to her knees and started sucking this guy off. He continued smoking his cigarette, holding it in one hand and using the other hand to stroke and caress her hair while she was servicing him. After a few more quick sucks, she put his cock back in his pants and led him by the hand to the house's backyard, where they disappeared into the shed where my friend kept his lawn mower and other tools.

I raced downstairs and headed towards the backyard. Once there, I quietly inched my way towards the shed, having helped my friend fix stuff around his house enough times that I knew the shed where he kept his tools had a window. Dropping to all fours, I peered into the window, ready to drop down and hide at a moment's notice if either of them spotted me. It took all my strength to keep from barging in and putting an end to all of it as I watched what was happening. My girlfriend was making out with him, unlocking lips only long enough to pull off her shirt and bra, those tight jeans looking even better now that they were the only thing she was wearing. I watched as my girlfriend pull his shirt off, kissed her way down his chest, down past his stomach until she was back on her knees, her face level with the bulge in the front of his pants. My girlfriend started kissing his cock through his jeans, running her tongue over it, until the newly-wed groom was breathing hard and begging her to pull it out and suck it. Ever the tease, I saw my girlfriend maintain eye contact with him as she took her time undoing his belt, undid his zipper and buttons so his jeans dropped to his ankles, and slowly pulled off his boxers with her teeth. Licking her lips as she stroked his cock, obviously enjoying having this guy in the palm of her hand, she told him to stick his cock between her tits. He obeyed instantly, and my girlfriend rewarded him by squeezing her firm breasts together around his shaft and letting him titty-fuck her.