I had been going out with Samantha for 2-3 years. Initially the sex was great. Samantha was a pretty girl, long black, hair, great tits, and a nice arse. The first 6 months were electric. We fucked on a train at night, we fucked in the men's toilets with blokes coming in and out, we even fucked in the office where we both worked. Our relationship started during a Christmas Works do. I had been trying for ages to get into Sam's knickers but she was seeing some dickhead who took her for granted. At the Works do, we were sat next to each other and I knew things were going to get better when she took my hand and guided it to her dripping pussy. She stood up, walked out, and I followed, all while her boyfriend was sat there boasting about his latest car to some people who didn't give a fuck. We went into her room, fucked, and went back down before her boyfriend even noticed. Within a few weeks, she had moved in with me. Anyway, we watched a lot of porn and, while I was bigger than Graeme, her boyfriend, I wasn't exactly huge. Quite a few times she would ask what it must be like to take a big cock. For the last three months of our relationship, things were getting tense. It was almost like I had no way of satisfying her sexually. Toby was a new bloke, working on IT, and I knew he fancied Sam. We often got into work arguments as we both disliked each other. I would often see him chatting to Sam, and this pissed me off. But, I didn't really want to get into any arguments with Sam, so pretended to stay cool. About 2-3 weeks after Toby arrived, I got home from work to find Sam sprawled on the bed pleasuring herself with a vibrator that was a little bigger than my cock. She saw me and told me to get in the bedroom. I went down on her dripping pussy, and brought her to an orgasm. When I went to fuck her, she pushed me away and said that "all you are good for is licking my pussy". The next day, Sam arrived home after me. She came upstairs, stripped naked, and I again licked her pussy. After a while, I realised that someone was watching us. It was that fucking geek, Toby. He was stood in just his trunks, showing an impressive bulge. "Toby reckons he's got an 8 inch cock, I brought him home to check" said Sam. She pushed my head back between her thighs and said "get me ready you useless fucker". I was furious but I did what she wanted and just hoped it was some sort of act. Eventually I felt Toby's hand on my shoulder as he pulled me away. His huge cock was now swaying in front of him as he rubbed it up and down Sam's dripping pussy. He pushed his cock in slowly, it was thick and long. With an inch or two left, Sam told him to stop. "Good, she can't take it" I thought. How wrong I was. She wrapped her legs around Toby and pushed him in until he was balls deep. I'll never forget Sam;s eyes as they disappeared into her head and she pulled at her long black hair. Toby fucked her, slowly at first, before building up speed. Sam was in heaven and, looking for something to add to the excitement, took my cock into her mouth. I could feel Sam sucking harder as she was obviously cumming. "I'm cumming too" Toby said. He started to pull his cock out, and Sam took her mouth from my cock before saying "In my fucking pussy, I need to be filled". Toby didn't flinch. He pushed his cock deep in her, and raised her legs so he could get even deeper. Toby's speed slowed down as he emptied his spunk into Sam's pussy. Sam kept sucking at my cock, albeit at a slower pace. I was close to cumming "I am cumming too" I said. Sam took my cock out of her mouth and said "Who the fuck cares?" I came and shot my load over Sam's tits, and then onto the bedding as Sam moved away. Sam then went to shower, followed by Toby. Toby left and Sam made no secret of her desire to fuck him again. I went to fuck her, but she pushed me away. I went down her body, and started to lick and suck her pussy lips. "That's good" she said "but from now on this is all you'll be getting. You're not good enough to satisfy me with that cock." For the next 2-3 months, I had to content myself with licking and sucking Sam's pussy. Often, this was with her trousers down just slightly as she didn't want to be naked in front of me. We slept in separate rooms, but when Toby came around she would invite me in to watch. I used to watch, with the hope of being allowed to join in and fuck Sam one more time. But, those days had long gone. For the last 2 or 3 times, when Toby left Sam told me to clean up her pussy and I did - tasting another man's cum for the first time. After a while, Sam moved out and I quit my job, and never saw either of them again.