I was 13; a shy kid who was clueless about sex. My dick was getting erect every morning and had grown in size to a respectable 5 inches, but I didn't know anything about masturbation. I was invited by a same-age boy in the neighborhood to join the Sex Club (really!) that he and two other neighborhood boys had just formed. I agreed, and we got together to play strip poker. Turned out to be just a way to slow down getting naked and initiating sex-play. When each of us gave up his last article of clothing, he had to lie down on his back and let the others feel up his boner and balls. When everyone was naked we did sword fights with our stiff cocks and more fondling. There was talk about "stroking it til the sperm shoots out", but no demonstration for some reason. When I got home, I made a beeline for the bathroom and pulled down my pants to try it out. I had jacked my boner for just a minute or two before cum sprayed all over the tile wall, and my knees threatened to collapse. Turned out my grip was way too tight, and my penis was red and puffy for a couple hours. Didn't stop me from doing it again the next day... and the next... etc!