I was thirteen at the time and had been masturbating as long as I could remember. I had no idea what sex was and never really had any education on the subject. None of my friends were the sort that would talk about it either. But it felt good and I would have orgasms, sometimes one after the other without knowing what they were.
When I started to get pubic hair, that was unexpected. At about the same time, I was in the shower one day and I noticed what I thought were little bits of white cotton wool on my penis. I was worried about it and almost told someone that I needed to see the doctor, but in the end was too embarrassed.
A couple of days later, I was masturbating in the bathroom. As I approached orgasm, I expected just the normal dry run. I had absolutely no understanding of what was happening, but this time I could feel things happening deeper inside me. I thought it was finished but it continued to feel good and then a small amount of liquid shot out. I was completely amazed.
By the next day I had done some research in the dictionary and encyclopaedia. I didn't know much, but enough to not ask for the doctor. I went to the bathroom again curious as to whether it would happen again or if it was just a rare one off event. I thought maybe I had done something differently, so I tried to do it in exactly the same way.
This time as I approached orgasm, there was an even stronger feeling that something was going on deep within the very base of my penis. I felt the warmth force its way quickly all the way up to the top and I've never felt it in quite the same way since. Again I was amazed as semen shot out in front of me in a series of spurts, and this time there was lots.
As time went on I gradually became used to it and gradually came to understand what was happening, but at the time it was a complete surprise.