My wife has five sister and only one brother who is 12 years younger than me. We spend every summer holiday with almost all of them at the beach. My brother in law and I always had a great relationship and we still have it, so we always talked about everything and we have lot of fun together.
I met my wife when he was just 12 and he instantly started to ask me lots of questions about growing up and sex. He had some many misconceptions and taboos and I know I made his sex life a bit more easy and pleasurable over all these years. He had quite a big trauma about masturbation and I told him than every men do it, that I do it and love it. I felt a sign of relief on him.
The years passed, we continued with our talking. I used to give him porn videos and magazines that he told me he enjoyed them a lot and also lent them to his friends, so I became an idol for the group. I noticed how he was growing up physical and mentally. He was very reserved to be naked in front of me but I noted that he fixed his eyes on my penis while changing my clothes and that he cover his parts while doing it but I always respected that.
My family in law have a house near the beach and most of them spend the summer together. It's a great opportunity to be all together the father, some of the brothers and now the third generation also. Before going back to the house and due to the quantity of people, we all have a shower at a facility at the beach. At the beginning the only men were my father in law, my brother in law and me.
One summer night, ten years ago, he told me that my dick was very big and thick, that I must be proud of it. I thanked him and he insisted that my measures were great and that his was smaller. I told him that the difference was mainly because of our ages that he was still growing and that he must had a normal one. I said that I could not see his penis those days and he showed quite embarrassed but he offered to show me it only if I showed him mine. I agreed and he pull down his pants and underwear. He was shaking and almost could not speak. His dick was quite small and thin (because of the tension I thought) and what shocked me was that I was very pale. Almost laughing I told him to relax that he was perfectly normal. He asked me to do what we promised, so I pulled down my pants and boxers. He said again than my size was higher than the standard and that surely my dick must be enormous while erect. I said that the same would happened to him. I mention that the size did not depended on people, that we must accepted what nature gave us and try to live and enjoy it.
Over the days, he always returned to that matter: the size. I found a porn magazine that had that topic and bought it to him. We read the article together and he asked me the length of my penis. I told him that a long time ago it was 16 cm while erect. He got stoned. He told me that he thought his was just 14! I insisted on the fact that he was still growing and that surely he would had a cock bigger than mine at my age. Looking at the magazine's photos, I noticed that he had an erection and joked about it and told him that I also had one. He asked to take the penises out just to compare. We did that and he couldn't believe the size of my tool. I told him that his thing was OK and that the differences between the two of us are that mine was thicker, darker and uncut and his was thinner, more pale and cut.
The last night, he asked me to help him with his luggage. The porn magazine was on top of his clothes so I took a look at it. I made some comments about some girls and so on. He pointed to my dick that was fully erect and I confessed I was quite hot. He told me that he feeling the same and I directly said that I needed a wank and I asked him if he would joined me. He stood up and we went to the bath and had a quick jack off. We finished at the same time and he told me that he enjoyed very much.
Back home, we met each other lots of times but never mentioned nothing at all till one day that he asked me if I had any video or magazine to watch together. I suggested to rent one and he told me to watched it at his home.
That day we started talking about our first wank together and planned what to get undressed and watch the video. We paid almost no attention to it. He asked lots of questions about my masturbation: my first time, my last time, my favorite technique, etc.; about the penis: the foreskin, balls, hair, etc.; about sex: first time, condoms, pussies, bubbies, etc. etc. etc.
We repeated that many times during almost five years. We tried using condoms, mutual and different techniques. We did it in long naked sessions and in a rush and with the clothes on, we did it in the woods and in the countryside. He told me in detail his first sex relation with a girl and next ones. We spent such a great time grabbing our tools and wanking together.
After a while he told me that he had discover a new world: he liked to be naked, to slept naked, that he loved masturbating and that he was not afraid to be naked in front of others. He said he didn't matter about size any more.
But five years ago he got a job and moved and actually is about to get married. He had no time to anything and he is absent to almost every family reunion.
Last summer he came with us to the beach house for a weekend. While having shower, I saw he was in the shower just in front of me and noticed that he was looking at my dick with a smile on his face. I instantly looked at his and retrieved a smile. I saw that he had grown up considerably but his dick has practically the same measures. I'm sure we both went back to those days! I wonder if we can repeat it someday!