I was at the gym with my dad and the most horrible thing happened.. I was on the sit-up machine and after some reps I felt some tingling down *there* and then 2 or 3 sit-ups later my penis like squeezed itslef - I couldn't control it - and some semen came out in some spurts. I was so embarassed - my dad asked what was wrong and I said I didn't know but it looked like I peed my shorts.
Has this ever happened to anyone before? Is this normal? How come this happened?