When I was a few years younger, I used to go over my friends house most afternoons for a swim. My friend's little sister, lets call her Suzy, was about 15 at the time. She and here friends would often all be in the pool and it would often make me hard watching all these young firm bodies playing around with bikinis on. After a few months, Suzy started to stare at me a bit more than normal and my friend told me that she had a crush on me. I noticed she would bump up against me in the pool and on one occasion pushed herself against me so hard that I felt her pubes rasp against the side of my thigh as she swam past.
She was a fairly good looking girl, perhaps a bit of puppy fat , which served to make her already big tits quite a bit bigger. I tried to play it cool and not give away how much she was turning me on. One afternoon she got into the pool and we started to wrestle. For a quick moment her foot brushed over my cock and she looked into my eyes straight afterwards. I excused myself and went inside to go to the toilet. The toilet adjoined the bathroom and I noticed the dirty linen hamper full of clothes. I had a quick look and saw pair of Suzy's panties, which I quickly grabbed and took into the bathroom with me. I inhaled their scent heavily while I jacked off and came like a bullet against the back of the toilet cistern. I dumped the panties back in the hamper and went back outside. This continued for four or five weeks, and whenever I was at my friends place I would make sure I got a few moments to use her panties. I started to notice that the panties were on the top of the hamper and I wondered whether she knew. This was confirmed one afternoon when I had just come and I heard a muffled sigh from the bathroom next door. I froze, knowing I'd been caught then blushed furious red realizing that someone was in the bathroom pleasuring themselves at the same time listening to me jacking off, which was probably quite loud . I quickly left the toilet and later noticed Suzy leaving the bathroom.
I decided next time I would make sure that she knew where I was going and I would see if she followed. Her parents and brother had gone to get take out food and a video and we were alone together in the house. I walked to the toilet, loudly closing the door and started to stroke my cock slowly but very firmly. Sure enough after about three minutes I heard some quiet noises coming from next door in the bath room. I raised my voice so I was moaning at about talking level and her sighs became louder until we were both making noise almost in sync. We both came and I walked to the edge of doorway and opened it, looking straight into her eyes. her face was flushed and she was obviously still feeling her orgasm. I leaned over and gave her a kiss on the lips and we heard the car enter the driveway. Her tongue flicked against my lips as we parted. She had her panties in her hand she pushed them into my pocket, grabbing my cock briefly in the process. I just managed to get my pants up just in time as her mom walked through the door.
That experience blew my mind and it happened in different ways many times after. They are other stories.