I think I have posted about this somewhere before. When I was about 9 or 10 my friend and I used to go into some of the bombed out buildings in the next block to us and masturbate. We never masturbated each other, just ourselves.
One evening as we were coming out of the building there was a man standing there and he said he knew what we had been doing. Not sure if he actually saw, or heard us.
Anyway we were both worried that we were going to get into trouble but he said "It's alright boys. I do it too" and we realised he had his penis in his hand and was stroking it.
Neither of us had seen an adult penis before and we were amazed at how big it was ( or seemed to us then).
After talking to us for a bit and continuing to stroke his penis, which we couldn't help staring at, he asked my friend if he wanted to touch it. I don't think he wanted to, he told me after he didn't want to touch it. Anyway the guy took my friend's hand and put it on his penis and wrapping his hand over my friend's, he continued to stroke his penis.
My friend pulled his hand away after a few minutes, the guy asked me if I wanted to feel it. For whatever reason, I was kind of fascinated by it and reached out and wrapped my hand around it and started to stroke him the way I stroke my own penis. I remember being surprised at how warm and soft the skin felt.
It didn't take more than a few strokes from me when he suddenly grunted and shot out several streams of cum. Some of it landing on my hand.
We had never seen anyone ejaculate, having only achieved dry orgasms ourselves. It truly amazed us.
After wiping my hand with his handkerchief he said he had to go, but it was nice to meet us and hoped we could meet again.
We changed the houses we used to masturbate in after that and never saw him again.
Something he said gave us the impression he was the estranged father of one of the girls in out street. She was three years younger than us and he said he used to put his penis between her legs and it felt good.
The guy was obviously a pedophile, although we didn't know anything about pedophelia back then. Thinking about it much later, I figured that was probably why he was estranged from the family.
My friend and I never really talked about it after, other than saying we didn't want to meet him again.
Did it affect me? I don't think so. I was very curious about sex from an early age and I think it was more a curiosity thing than anything else.
He never tried to touch us, other than grabbing my friend's hand to put it on his penis.