My sister is four years older than me and was mostly a total bitch when we were kids. She often got stuck babysitting me and I am sure that has a lot to do with how mean she was at times.
The summer after 6th grade we were given permission to use the next door neighbors pool while they went to stay in another state with one of their kids. We would get up in the morning, have breakfast, do chores and then change into swimsuits so we could go swim.
One day I had put on my swim shorts and headed for the door as my sister was usually ready and waiting. This time as I passed by her room she was standing in front of the mirror posing and looking at herself from the side, the other side and then turning to try and see he backside.
As I stood there looking at her I realised for the first time that my sister was actually pretty hot. She was tan with small but perky breasts that were slightly banana shaped and very firm looking. Her nipples were big and erect as they often were and usually visible even if wearing a bra. Her pubic hair was light and trimmed in the shape of a small triangle.
Lost in my gaze I suddenly hear her say what are you looking at pervert. Shit I thought now I am going to have to deal with her being mean all day. But to my surprise she then asked why I was staring and if I thought she had a nice body. I just said I don't know I guess it's alright. She smiled and said thanks while leaning towards the door and closing it in my face.
We went to the pool and when she took off her shirt and shorts I saw she was wearing a new much smaller bikini. It was smaller to the point I could see the tan lines from the other one. I was definitely liking it and had to hurry into the water to hide my arousal.
After a while she sat with her legs in the water only leaning back on her hands with head back like one would do to get full sun. I swam underwater to wear she was and when I surfaced I was directly in front of her. Her legs were spread slightly and I could see the shape of her labia and even her bush through her damp bikini.
When it was time to go back home we grabbed what we had brought and locked the gate. When we got to our door I was still dripping wet and trying not to let her see that I was still half erect from looking at her. To my dismay she said I couldn't go in the house dripping wet and started to dry me off. Then it happened. She was rubbing the towel all over me and felt my erection.
She looked a bit stunned when she felt my boner and asked if it was because of her. I said I don't know maybe. We went inside and she told me to follow her to her room. She shut the door and said never to tell anyone what we were about to do or she would kill me. She took off her bikini and then pulled my shorts down. As I stood next to the bed where she was sitting she reached out and took my hand and placed it on her boob. With her other hand she grabbed my dick and started stroking it.
You're pretty big she told me and asked if I liked touching her. I nodded in the affirmative and she then put my hand between her legs. Her skin was cold from having been wet which made her pussy feel almost hot and steamy. She used one of my fingers to penetrate herself and I couldn't believe how warm and slippery wet it was.
She then pulled me close to her and told me to put my dick in her just like she had done with my finger. She scooted close to the edge of the bed and raised her legs so her ankles were up by her head. As I fumbled around trying to put my dick in she reached down and guided me inside of her. The sensation felt amazing and I instinctually began moving in and out of her.
I watched in amazement as her hand moved almost in a blur as she rubbed herself. Soon her breathing was choppy and her hand slowed a bit now in a very deliberate circular motion. She lurched forward many times with each one letting out a gasp. Then I felt something I had never felt before which felt like a tingling tickle combined with electricity in my dick. I felt several spasms and she pushed me back saying not inside me.
Turns out I hadn't actually produced any semen to her relief. She asked if I had ever cum before and I said no. It wasn't until a few weeks later that I started to ejaculate and from that day on I was either trying to get pussy or masturbating most often both. We had sex probably 100 times over that summer and once several years later but never talk about it.