I was in my early to mid-twenties when this particular incident occured. A couple of friends and myself used to go fishing overnight in the ocean. It was early in the morning when we were fishing off a jetty and it happened. I had my line in the water and pole between my legs right up against my cock. I started to see if I had a bite, so I lifted my pole up and when I did it stroked my cock and sent a jolt of electricity through me. It was early and I was getting horny, so I decided to continue.
My friends were off on another part of the jetty, so I continued moving my pole up and down over my now rock-hard cock. It felt so good and I could feel the pre-cum starting to ooze out of the head of my penis. I kept going and going, but rubbing faster ever so slightly as to not raise the suspicions of my friends. Then I was on the edge and finally, on the last stroke, I exploded in my underwear. I had a huge cum spot in my underwear and on the outside of my pants.
On the way home, we stopped at a store for something to eat and drink. I had to tell my friends that a wave came up and splashed me. They never found out and I had some serious fun fishing!