First Time I Discovered Masturbation

I was 13 years old when I first discovered masturbation. I walked around the house with, what was a pair of long shorts that were too tight. I didn't get an erection, just felt my foreskin roll down, and my penis head to gently rub my trunk shorts. After a night of swimming, I wanted to know more about this feeling. I locked myself in the basement bathroom, got erect, and tried pulling my foreking up and down. It was slow to start, then faster, and felt sudden electric-like pulses. After a few minutes, I felt a sharp muscular squeeze, got up and saw my white ejaculate squirting. I stopped, moaned and thought I was ill. From that day on, during my teen years, I masturbated 3 times a day.