Friend's Little Sister Topless

Billy and Cindy were a brother-sister duo I knew as a teen. Billy and I were very good friends, as we sat next to each other in most of our classes at school. I also knew Cindy quite well, as the three of us played with each other a lot when we were younger. The siblings were athletic, popular, good looking, and had a good natured relationship with each other.

Anyway, there was a time when Billy and I were 15, and Cindy was 13 - we were hanging out at their family’s large two story house, which had a small pool in the backyard. It was a warm summer’s day - not boiling hot, but hot enough to make the pool look very enticing. The three of us were by ourselves as Billy and Cindy’s parents were out. When it was time for a swim, we changed into our swimsuits. Billy wore plain black shorts, Cindy wore a light blue bikini which was a few years old, and I wore my tight blue swim briefs.

We had only been swimming for a few minutes when Billy and I noticed Cindy kept adjusting her bikini top, stretching it out as it seemed too tight on her. I suppose that, because the swimsuit was a few years’ old - and the fact that Cindy’s body had begun to develop - the top was now too small for her to wear comfortably. Billy slyly suggested to his sister that she should just swim without the top and that there wasn’t that much to see anyway, pointing at her breasts. Cindy glared coldly at her brother for a few seconds, but soon there was a small smile on her face, indicating she wasn’t really bothered by her brother’s joke.

To my surprise, Cindy immediately began to undo her bikini top! She threw it to the side of the pool, revealing her young, developing breasts in all their glory. They weren’t huge yet - just an A or B cup - but they did point out from her body a little bit, and her nipples were much larger than before. I stared at them for a bit before looking away out of politeness. We continued swimming and splashing each other in the pool. I tried my best to not let Cindy’s topless body bother me, but I couldn’t help it! Every time she and I were close to each other, I could feel myself getting hard. For the hour or so we were in the pool, I was either fully hard or semi hard. I don’t think my dick ever had time to rest!

After they had enough of the pool, Billy and Cindy decided to go back into the house. I told them I would stay in the pool for a few more minutes. I didn’t want to get out yet because my raging hard on would be immediately obvious in my tight swim briefs. As the siblings headed towards the house, I took one last glance at Cindy and her cute topless body. I also looked at her nice butt in her tight bikini bottoms, which were riding up her butt crack. I was fully hard and desperately needed to rub myself, but as I didn’t want to get out, I guess I had to do it in the pool!

I hung on to the edge of the pool closest to the house with my left hand, with my right hand sliding over my chest and stomach before reaching my crotch. My boner filled my swim briefs, with the tip busting to get out of the waistband. I slid my hand over the thin, silky fabric of the swimsuit and rubbed like there was no tomorrow. I was so horny, having just seen a half naked teen girl, that it took less than a minute to get that “feeling”. As I felt the climax coming closer, I knew I was going to moan loudly, so I ducked my head underwater to cover the sounds. My legs were thrashing under the water, my arms were trembling as shot after shot of hot cum exploded in my swimsuit, filling the suit and seeping through to the chlorinated pool water. 

Feeling slightly guilty but relieved, I resurfaced and continued to hang on to the edge of the pool, feeling my boner slowly getting softer.

Then, a sweet voice close by asked me if I was ready to get out of the pool.

I looked up at Cindy leaning over the pool, and ended up staring directly at her small breasts drooping over me.

I got hard again, in an instant.

Oh dear…