Climbing Climaxes

When I was a kid I was one of those guys who figured out he got a funny feeling in his pants when climbing on stuff. I remember noticing it when climbing the poles at my elementary school, like something was happening, but for a while I'd just ignore it.
But, one time my friends and I were climbing around on the monkey bars. It was a big set, with room for kids to go back and forth side by side, and most were hanging out on the top. There was plenty of room to fool around without being in anybody's way. I decided to climb up along one of the corners, up a pole.
It felt really good, and if I struggled a bit, it felt even better. It didn't take long before I was close to cumming. I didn't know what it was and I was too young to actually ejaculate, bit I could tell something good was happening and I pretended to have trouble getting to the top. One of my friends noticed I seemed to be having and laughed at me, "he can't get up!" but I didn't care. I came moments later, and climbed up easily after that. I've read other "climbers" can tell when they see someone enjoying a pole but if any other kids had a clue what I was up to they didn't let on, and I never told anyone.

I kept climbing on stuff and enjoying it until I started ejaculating, and by then I had become pretty shy and nervous that other people really would catch on, so I kinda forgot about it and had figured out other ways to masturbate anyway.
The last time it happened was in high school. I hadn't done it in a long time and wasn't really thinking about it. I think I was a freshman. We were doing a flexed arm hang in PE, with the teacher timing us. I wasn't real athletic, but as soon as I was hanging on that bar I knew I could hold it for a long time, I could have easily had one of the best times in the class. Other students were actually cheering! Then I could feel it--i hadn't been hanging on long when I felt a boner forming, and my gym shorts would have shown everything. It felt amazing already but I was so embarrassed that I let go immediately before anyone could notice. I think it would have been a disaster but I wish I could have hung on and cum in front of everyone, ha ha ha.