...and I've been addicted to it ever since.
I was about 14 and this guy, Guy (yes has name was Guy), who I sat next to at school would occasionally get a hardon in his trousers (we used to call it a 'fat') and show me, still inside his pants, and then let me feel it.
One day he invited me to his place after school and when we were in his room he asked me if I masturbated. To be honest I'd never even heard of it so without saying anything he took out his soft dick and started playing with it. It was a lot bigger than mine and I was fascinated. When it was hard and REALLY big he started moving his hand up and down on it. I had no idea what was going on. He started to get a weird expression on his face and suddenly said, 'It's coming'.
I still had no idea what was happening but suddenly several gobs of thick white stuff flew out of his piss-hole and landed on the carpet. I was totally amazed and very excited by all this and he said, 'Now let me do you'. But I was embarrassed, as my dick was nowhere near his size, and I wasn't sure about letting anyone else touch me so I hurriedly escaped.
As soon as I got home I went to the safest place I could think of... under the house. There I pulled my dick out and tried it for myself. What a sensation that first time is... my body seemed to go into a spasm and I produced some fairly watery cum. But I knew I was a man. And ever since I've smelt that musty under-the-house smell I remember that first experience.