This happened when I was 13. I attended to an English Grammar School. A pal and I were keen stamp collectors. One Friday in summer, we fixed up to ride our bikes to a town 10 miles away where there was a shop which sold large packets of world stamps, unsorted. We were each going to buy one, sort out what we wanted, and with the rest we would make up another collection, which we would put into an auction sale. (His Mum worked for the auctioneers). Saturday morning my mum made a pack of sandwiches for me and a flask of cold drink. I called at his house, as arranged, at 11 am, only to be told by his Dad he was ill in bed with an asthma attack. I went up to see him, and, boy he was bad! He said you go and get the stamps for both of us. I rode the 10 miles to the shop and bought 2 large packs of the stamps. Riding back home round the quiet lanes I looked for somewhere to stop for my lunch. I saw an open gate to a field, and inside there were some bales of hay. I took the bike inside, and sat on a bale and ate my grub. Just as I was finishing, I heard a noise and into the field came a tractor and trailer driven by a woman, with 3 men on the trailer. I got up quickly and was about to apologise for being in their field when a voice from the tractor said 'Hi'. I realised it was Bob, a boy I knew from school. We were in the same year, but not in the same group. He asked if I'd like to help. I asked how. Help me stack the bales on the trailer he said. I jumped on the trailer, and the other two men - his Dad and an uncle,used pitchforks to lift the bales onto the trailer. He told me his mum was driving the tractor and they were shorthanded because his other uncle had been called away. He showed me how to stack them so they were safe. It was hot and dusty hard work for me. Bob was a lot bigger than me and stacked about 2 to my 1. Eventually we headed back to their farm, where the trailer was unloaded into the barn. Then off back to the field. I heard his Dad say 'we might just manage it'. I asked Bob what he meant. Bob said there were thunderstorms on the way and if the hay got wet it would be ruined. This time there was just half a load, and before returning to the farm they hoisted my bike onto the trailer. We had just unloaded the hay into the barn when there was an almighty clap of thunder and it started raining. We ran into the house and his mum said 'you won't be able to ride home in this. Ring home and tell your mum we'll bring you home later, after a meal' This I did. She then told Bob that we were both filthy dirty and to get a shower. Bob got a couple of towels and took me to his room. We undressed, and I couldn't help seeing Bob was a big lad, with quite a bit of hair around his Willie. He took me along the corridor to the biggest bathroom I've seen. There was a bath, and also a large walk-in shower. He told me that it was an unused bedroom converted to a bathroom by one of his uncles. He turned on the shower, and we stepped inside. Being rather shy I had my back to him. He asked me if I would like him to wash my back. I said O.K. He then started to very gently rub my back, which I found pleasant. As he moved down my back I began to feel my penis start to stir. Eventually as he got down to my lower back it was just begin to thicken and looked as if it was about to rise. I felt embarrassed and didn't know what do. Suddenly I had an idea. 'Would you like me to do your back' I asked, hoping that when he stopped touching me things would return to normal. 'Yes, please' he said. I turned slowly round and found he too had turned round. I started soaping his back, and rubbing it just as he had done to me. But to my horror I found that my penis was still being aroused. In my confusion I dropped the soap. He hit my knee on the way down and slithered round the shower landing at Bob's feet. He bent down to pick it up, taking half a step backward in order to do so. As he did so his backside touched my half erect penis. He turned to me,pointed at it, and said 'I felt that!' I was mortified, but then I saw that not only was he smiling but his penis was also in a similar state. 'How long has it been like that' he asked. 'Since you started washing my back' I told him. I asked him when had his started to rise. He said 'when I started to wash your back!' Then he said 'might as well let them go the whole way', and reached out and held my penis. I did the same to him, and very quickly they both became fully erect. We just looked at them for a moment or two before he said we should get dried off because he mum would be getting some food ready for us. We dried off most of the water and headed back to his room to finish off and get dressed. By this time mine erection had not quite subsided, but I was no longer worried about him seeing it. He said he could see that I was circumcised and asked me when it was done. I told him I thought it had been down when I was a baby and had had a hernia operation. I showed him the white scar in my groin, which could be seen through the small amount of hair I had there. I commented that I could see he had not been circumcised, and didn't need to be. When I had first seen it the foreskin was covering the glans, but when erect the glans was exposed. He just laughed. Talking about it was making them both stand up again. He asked if I could produce sperm. I said yes. He said 'shall we go for it?' I said 'OK, if you like' He laid on the bed and I took his penis and gently stroked it. After a few minutes he said 'nearly there'. I felt it go extra hard and then he came, catching it in his towel. I then laid on the bed and he rubbed mine. It felt great, and eventually I spurted out into my towel. 'Thanks' I said,'that was great'. He asked if I had done it before. I confessed that it was the first time anyone had masturbated me, but that with a mate from my junior school we had stroked each other willies to erection, but no more. He said he had done the same, but had also been masturbated by his cousin, who was 2 years older, several times. After a meal, his Dad took me and the bike home in their pick-up. When we got to my house, my Dad came out to thank him for bringing me home. They looked at each other -- and starting laughing. It turned out that they were the same age and had been to school together. Bob's Dad said he had looked at me, but couldn't work out why my face seemed familiar!
The following day I took the stamps round to my pal. I never mentioned what had happened at Bob's. We eventually made up two collections from the stamps we didn't want and sold them at auction. We actually got back more than we paid for them. Of course, I saw Bob often at school, but what happened that day was never mentioned by either of us.