Back when I was 13, my parents decided I needed to exercise more and not just spend all my time playing video games. My dad used to go to the local swimming pool every Saturday morning, and mum suggested that I join him. I hated waking up early which was one of the reasons I was sometimes late for school. Anyway, I had no choice but to go, with my dad telling me he would buy some glazed doughnuts for breakfast as a treat, so that cheered me up slightly.
Anyway, I got to the pool in my old pair of black board shorts. When I first got them a few years ago, they were quite oversized but now they fit well. Dad was doing laps in the large pool and he told me I could go in the leisure pool as long as I didn't stay still and actually swam from time to time.
About half an hour into my session, I noticed a boy around my age enter the pool. He had short blonde hair, a nice smooth face and slightly muscular body. But what was interesting about him was he was wearing a pair of tight light-blue swim briefs. In my area, pretty much all the kids my age wore shorts for swimming, so seeing a boy wearing swim briefs was surprising and a bit strange.
As much as I tried not to look at him too much, the boy's swim briefs looked great on him. They were fairly tight and clung to his body. His butt cheeks looked nice and round and his small bulge was turning me on. He wasn't hard or anything but he seemed to have a decent sized soft dick for his age. Suddenly, my mind was flooded with thoughts of me wearing one of those swimsuits to swim in. My penis became semi-hard during these thoughts but settled down as I continued swimming.
When my dad said it was time to go, we changed back into our regular clothes and he asked me whether I had a good time. I said it was alright and asked if we could go to the pool's swimwear shop to buy me a new suit. My dad agreed, seemingly glad that I was showing interest in swimming. The shop was quite small so I instantly found what I was looking for - a pair of light-blue swim briefs just like the one the boy had! As I felt them in my hand I marvelled at how soft and smooth the material was. I couldn't wait to try them on!
There wasn't a try on room at the store so I guessed my size (choosing a slightly smaller size than usual because I wanted a tight fit), took that size off the rack and paid for them. After a delicious glazed doughnut breakfast, my dad and I headed home with my new swimsuit. I quickly went to my room and closed the door. Taking the blue swim briefs out of the bag it came in, I ripped off the tags with my hands and got naked.
Excitedly, I pulled the swimsuit over my legs and onto my crotch. Wow! What an interesting feeling! I instantly loved it and noticed my dick getting stiffer and stiffer inside the swim briefs. I went up to the large mirror which was hung on the back of my door and marvelled at how my hips, butt and boner felt and looked in my brand new swim briefs.
In regards to masturbation, at that age I knew what the basics were from my friends, and had tried to stroke my penis a few times, but it never really worked for me. Now with my new swimsuit, I decided it might be time to try again. I got on my bed and put my pillow in the middle of the bed. Then I put my crotch on the pillow, face down, and proceeded to slowly hump my pillow up and down.
Instantly, I knew it was working better than any time I had tried before. I imagined I was back at the pool with the blonde haired boy and we were swimming together. For a few minutes I humped and humped, gradually changing my speed from slower to faster. Then, an amazing sensation came over me. I felt like I had to pee but instead of stopping I continued on. My balls were tightening, my four inch boner throbbing as I gripped my bed as a new, strange substance left my penis.
Breathing fast and overwhelmed with shock and surprise, I looked down at my swimsuit to see a small wet patch on the front. I reached inside the swim briefs, and when I ejected my hand there was a small amount of white sticky semen on my hand. I had done it! My dick was softening but as I played with the sticky stuff on my hands it instantly became hard again. I came a few more times in the next hour, ecstatic at my new skill.
Overall, it was a great morning and I was looking forward to more swim brief adventures!