I had been with my then girlfriend for about 4 years. Sex was good when she was up for it. I had fantasied of her with another man many times but whenever I brought it up she never seemed bothered. One weekend we had a hotel booked and tickets to a gig in the big smoke. We checked into the hotel on the Friday evening and were getting ready to head into the concert. I jumped in the shower first and then she went in for one. I laid on the bed waiting for her to finish. When she was done we had a quickie where I brought up the idea of a threesome again. This time the idea seemed to turn her on. We got ready and she looked amazing. Her blonde hair was curled to perfection, she wore a low cut top that her tits were bulging out of it and should lots of cleavage, a little short skirt that showed off her short legs and killer high heels. We went off to the concert and then into town for a few drinks afterwards. After a few we were both feeling happy, i noticed she was eyeing up a tanned man at the bar. I gave her money to get our last drink as we agreed we would head back to the hotel. I noticed her flirting with the tanned man at the bar, she came back with the drinks and when I asked she said it was just a friendly chat. We finished our drinks and got a taxi back to the hotel. We decided to have a night cap in the residents bar in the hotel. We were sitting in the corner and it was very quite. We were going to head upstairs when the tanned man from the bar arrived. He ordered and a drink and my girlfriend boldly asked him to join us. I knew by her tone we were game on. We had another round of drinks, it turned out Dave the tanned man was staying on his own on business. I went to the toilet and when I walked back in I couldn't believe my eyes, my girlfriend, Rose was groping his cock and he had his hand on her leg, I got an instant hard on. Dave asked if we would like to go back to his room and Rose jumped at the chance. Dave told us his room number and told us to have a chat before we decided and off he went. Rose was mad for it to happen. We arrived to his door and he let us in straight away, Rose wrapped her arms around Dave and they started to kiss, she worked her hands down to his trousers and started to fondle with his cock while he was feeling her tits. He helped her out of her top and her big tits were free, she had no bra on which made me so hard, she undid his trousers and released his cock, she gasped at the size of it, it was about 3 inches bigger than mine and a bit thicker. She fell to her knees and started sucking it. It was an incredible sight. She stopped sucking and told me to undress and join them, then she wrapped her tits around Dave's cock and gave him one of the best titwanks I'd ever seen. She lay on the bed and told me to start licking her to get her ready for Dave's monster cock and I obliged while she sucked his cock on again. I licked for awhile and then mounted her on the bed while she was still sucking. She was moaning loadly when she told me and Dave to swap places, he was putting a condom on when she told him he didn't need it as she wanted to feel it inside her, as he entered her she was mesmerised, I'd never seen her like this before. He worked his way in inch by inch and was eventually balls deep, his balls pounding off her. She orgasmed at least 3 times while he was fucking her and she was sucking my dick, I was going to cum soon as was Dave. She sat up and told us both to try cum on her big tits at the same time, she was jerking us both off at the same time we both exploded over her incredible tits. We cleaned up and went off to bed, it was the first of many threesome adventures.