My name is Will, and this is the story of something I that I never in my wildest dreams thought would happen. My girlfriend and I had been together for about 4 years, we were both 22 and recently graduated from college. We had a nice little apartment in the city at the time. We were quite happy, and had a fabulous sex life. My girlfriend, Tracy, is a sexy blonde about 5'6". She has a tight, toned body with nice firm B cup tits and a great ass. We were both pretty sexually open, and had fantasized together about having a threesome with another girl, but nothing had come of it as of yet.
One weekend Tracy's sister Nikki came to visit. She was on break from her college, where she was a sophomore. Nikki was just as hot as her sister, in a slightly different way. Nikki was darker blonde, about 5'5", with softer features than her sisters. She had amazing C cup tits, but a smaller ass then her sister. I had often thought about fucking Nikki, or fucking them both at the same time. I even admitted to having a dream about it to Tracy, and surprisingly she took it in stride, saying, "how could you help it when we're both so good looking?" with a wink. In fact Tracy admitted to having the occasional naughty dream involving her sister.
Nikki arrived on a Friday afternoon, a little upset about a fight she was having with her boyfriend. Tracy and I sat her down to talk about it. It was mostly the two girls talking but I picked up that the guy was being an asshole to her, and that she didn't think she would stay with him because, as Nikki put it, "he's got a small dick anyway so he's doing me no good!" We managed to cheer her up, then we all went out to dinner and had a great time. We decided to just relax that night and watch a movie.
When we got back the girls said they were going to change into comfortable cloths to watch the movie, so I did the same. I threw on some workout shorts and a T-shirt and plopped down on the couch. A few minutes later Nikki and Tracy came in. Tracy was wearing thin blue pajama pants worn low across her hips and a tight white tank-top, obviously with no bra. Nikki had on some dangerously short cotton shorts that showed off her ass and a t-shirt, also without a bra. Tracy sat down in our big lounge chair and put her feet up, while Nikki sat down next to me. Nikki was always really comfortable physically with me, always giving me hugs and things, and Trace didn't think anything of her sister sitting next to me.
I turned the lights off and started the movie. It was pretty late, and Tracy seemed to fall asleep in the arm-chair quickly. Nikki, too was getting tired and lay down on the couch, putting her head in my lap. Now this was too strange, I knew how comfortable she was with me. I didn't know if she was asleep or not, so I just tried to keep calm with this cute 19 year-old's head inches from my dick. Unfortunately there was a sex scene in the movie, with some pretty graphic stuff, and I started to feel myself get hard. I was praying that Nikki didn't notice, but those hopes were dashed when she slowly turned towards me. To my surprise there was a little smile on her face.
"Getting a little excited, huh?" She said.
I tried to laugh it off, "haha, sorry about that."
"Don't be," She said as her smile disappeared and something else crept into her eyes, "Tracy has told me how nice your cock is, I've been wanting to find out for myself." At this point Nikki, still lying in my lap, slides her hand under my shorts and up my leg. I should have stopped it there, but really, how could I? Her hand snaked up my right leg to my boxers, and then slipped under those until she came to my cock. I'm on the bigger side of normal in that area, about 7", and straight and thick. As her fingers ran up the length of my member her eyes rolled back a little. When she got to the base she slowly wrapped her hand around my cock, her mouth falling open as she gasped at my size. All I could do was stare at her. She squeezed and stroked my dick for a few minutes, then sat up a little and pulled down my shorts so my cock sprung free. Then Nikki lay back down and rested her head on my thigh, grasped my cock at its base and opened her mouth. Slowly she guided it into her mouth, then took it deeper and deeper in. She softly sucked on the top half of my dick, looking straight into my eyes, not saying a word. With me still in her mouth she lifted up her T-shirt up above her tits, and rubbed her hands all over them. She took one hand and ran it down her body, into her shorts and started touching herself.
I was in utter disbelief, but couldn't help myself. I grabbed those gorgeous full tits in my hand and rubbed her nipples as she sucked me. She started moaning with my cock in her mouth and squirming as she fingered her pussy. We both realized she might be too loud, so she quietly sat up. As I took off my shirt she slid out of her shorts. Nikki then knelt down in front of me, T-shirt still up above her tits, knees spread on the floor, displaying her clean shaven pussy. Her hair was up in a pony tail with some falling across one of her eyes. She looked sexy as hell. I sat with my legs open and she grasped the base of my cock with one hand and gently cupped my balls with the other. She then sunk her mouth down on my dick and started sucking me again. I was in heaven watching this young girl's head bob up and down on my cock.
At this point I looked over to see if Tracy was still asleep. She was lying facing us on the reclining chair, and seemed to be motionless. Then I realized her hand was down her pajama pants, and it seemed like her eyes might be open. I almost jumped up, but then saw her other hand move, and pull the top of her tank-top down under her nice firm tits, and start playing with them. She was watching! Even more amazing, she was enjoying it! Soon Tracy realized I had seen her, and sat up. She put on finger to her lips, signaling me to keep quiet (Nikki was facing away from her as she blew me). She then sucked her finger as she pulled off her pants, then tank top. I had her sister blowing me while my girlfriend stripped! Tracy sat back down and spread her legs and began to finger her shaved pussy for me.