My sister(33f) and I(29m) have always had a really close relationship. As kids, we always were hanging around each other and keeping each other company. By the time my sister, let's call her Lauren, was 12, my parents would let her watch me whenever my parents had to go out.

One weekend, about a year in to my sister watching me(I was 9 and she was 13), we were messing around roughhousing and somehow I ended right on top of Lauren. I accidentally pulled on her shirt, revealing her barely there tits covered by a training bra. I could just start to feel her training bra tits against my chest through my shirt. I was young, but it felt sooooooo hot feeling her tiny teenage tits against my chest. I don't remember how it happened, but next thing I remember, she was making out with me and my hands were gliding all over her body. I was still a virgin too, so obviously I was very curious and started to undress my sister. We didn't really know what to do then, so I ended up just sucking in her tiny, growing tits, which made start to moan. I kissed every inch of her body that day, from her back to her boobs to her legs and virgin pussy. She was still a virgin too, and I think after that she got nervous, so we got dressed and went about our day.

A few weeks later, we were on our way to school with our mom driving us. I don't remember exactly how it started, but we were both super horny again and our mom wasn't paying attention so after groping her tits again some more, I put my hand down Lauren's pants. I fumbled around for a bit, not knowing really what to do. After a few hits and misses like this lol, she guided my finger to her pussy. She was so tight that it took me a sec to get my finger wet enough to slide inside her, but finally I did. The burning lust in her eyes told me everything i needed to know. I began 5o move my finger in and out in and out in and out of her pussy. She was trying her best to stay quiet to not alert our mom, but I could see and feel the pleasure burning in her eyes, biting her lip to hold in a moan. She started to get really really wet, let out a really deep sigh and I felt my sister's virgin pussy convulse and spasm on my finger. I didn't really know what I was doing, but we were close to where I got dropped off at at my school, so I took my finger out of her pussy slowly and then put my finger in my mouth and licked my sister's juices off my finger and walked in to my school. Still being young, I was worried I had made my sister pee herself because she had gotten so wet lol until she later explained to me that I had given her her very first orgasm.

Theres more stories too, but I'll wait and see how these do before getting in to more.