It was in my sophomore year in high school and I had a biology class where we were paired with another student. I was paired with a girl I had seen around the school before but had never talked to. She was kinda cute and was on the basketball team, and we got along pretty well from the start. A couple months into the year we were given a project that had to be done on our own time, so I was going to meet her at her house that night. She only lived a few streets over so I just walked, but they weren't home yet. I sat on their porch for about 10 minutes until they pulled up and she apologized and told me their practice ran a little long. She didn't even get changed afterwards, still in her shiny purple uniform and sandals. We went upstairs and she asked if I minded if she took a quick shower, and I said it was no problem and she said to make myself at home. I stood there for a minute then decided to get more comfortable because I was going to be there a while, so I pulled off my shoes and socks and sat on her bed, watching some TV. She came back maybe 15 minutes later wearing sweatpants and a tank top, but with no bra.
We dealt with the work for a little while, but I couldn't help looking down her shirt every time she leaned over, and the bulge in my jeans kind of gave it away. She noticed it and kept smiling, but it just wasn't going away. She looked pretty damn hot the way she was, hair still damp and hanging down, toes painted bright red and of course, her moderately large tits hanging freely. She finally spoke up and said 'maybe I should've dressed a little less casual?' I said I was sorry and I couldn't help it, but she said not to feel bad and it actually made her feel kind of sexy. We talked for a little while about it when she asked me if watching her made me need to cum. I kind of laughed and said 'a little'. She told me to lean back so I did, and she unzipped my jeans and yanked out my hard penis. I pulled off my shirt and asked her what about her parents, and she said she told them we were going to be studying and not to bother us. I just smiled and leaned back with my hands behind my head as she sat between my legs, a foot on each side stroking my fire-hot dick.
She was at it for a few minutes when she told me to hang on, then got up and grabbed a bottle of baby oil out of her dresser. I asked why she had it and she told me she puts it on her vibrator to make it extra slippery. I almost came just hearing that she masturbated all the time with a vibe. She poured some in her hands then grabbed onto me, squeezing the shaft with one hand and kneading the head with the other. I had never felt anything like it before, I couldn't even lay still it felt so amazing. I was lucky if I lasted two minutes like that when I told her I was going to cum, so she started making long strokes, from the base all the way up to the tip. It was agonizing how badly I needed to cum and her slowing down delayed it, but that made it better because when it finally brought me to my peak my penis spewed out more cum than I had ever seen before. Five or six thick ropes of cum shot out all over me, the rest covering her hands as she kept stroking me. I couldn't believe I stayed hard after that amazing cum, but I did. About 10 minutes later I squeaked out that it was going to happen again so she sped up, playing with my balls with the other hand. I tried to stay silent but I couldn't help but grunt as I came a second time, two thin lines shooting out and I was done for. I couldn't hardly breathe it felt so amazing, and I told her that was the best thing I had ever felt. She smiled and snuck off to the bathroom, grabbing me a towel to clean off with.
When she got back she giggled and told me she was soaking wet. I wiped off the cum and laid her on her side and got behind her, reaching under her waistband and finding her slick pussy, rubbing her lips and playing with her clit. Her breathing sped up and told me that was the perfect spot and how good it felt. She maneuvered and made her way out of her shirt, squeezing her naked breasts, her nipples turning pointy and hard. Her eyes were clamped shut and she kept whispering 'yes...yes...yes...' as my hand was now covered in her pussy juice. She started wiggling around but I kept at it, and out of nowhere I heard 'oh..ohhh....unnnngggghhhhhh!' Her legs spread apart and she came hard, twisting around and grabbing her pussy, squeezing it through her pants. She caught her breath and told me that was incredible. She just laid there motionless with her eyes closed for a minute as I rubbed her juices all over her bare belly. She looked at me and smiled, then said we should probably get a little more work done. I agreed and we cracked open our books again, both of us still shirtless and barefoot. We stayed that way until about 9:00 when I had to get going, so I got dressed and she walked me to the door. When I got home I jerked off again before I went to bed, my penis still feeling soft from the massage she gave it before.
This went on a couple more times, and even though she wasn't ready to have sex we had fun, one time us both getting naked and masturbating together, me kneeling in front of her, her on her back and feet against my chest. Sadly her mom had to switch jobs and her new one was out of state, so about a week later she had to move. The day before she came over to my house and we spent the evening naked in my room (luckily my parents were gone), giving ourselves and each other loud, sweaty orgasms. I think in three hours, somehow she made me cum five times. By the last one it almost hurt, but at the same time it felt so good.
The year went on and my new lab partner was a guy, and while he was cool, there was no way anything in that class could ever match what we did for those few weeks.