It wasn't that I told my parents or we had a discussion, but they had a discussion on what they'd casually seen.
It turns out that my mom told my dad that she noticed my dick showed when I was wearing swim trunks. That was early the summer when I was 11 and had a growth spurt that spring in 4th grade. My mom told my dad that I needed to wear a jock under my swim suit, but he said it wasn't necessary because the suit had a liner. She said she didn't like seeing my penis so visible when I'd get out of the pool and the wet swim suit was clinging to it. (I have a pool at my house now, and had a deja vu of that when I got out of the pool on July 4th and my mom was sitting there watching us swim and play in the water. I made sure I pulled the wet suit off my package...lol)
Back when I was 11, my mom bought a jock at JC Penney's and gave it to my dad to give me a talk and let me know why I needed to wear it. He reluctantly took me aside and said that if I was going to continue playing sports, I was going to wear one at some point, so I might as well get used to it then. He also took me to the store to buy swim trunks that were larger. I remember wearing the older pair another time to the rec dept pool, and my best friend making a comment about my dick showing.
That summer my family also took a two week trip camping in the northeast and Canada. We met up with a family we knew who lived on PEI. I remember showering and changing with my dad, the other dad and his sons, and whoever was in the shower rooms. Although I'm a grower, I was larger at that age than the other dad. I realized on that trip that my dick looked like my dad's, and when I got back on my baseball team after vacation, he made sure I wore a jock and cup every game.
Since that time when I was 11, I've seen other male family members on my dad's side, and most of us have the same dick. Bad sinuses and big dicks must go together in our family. lol | 
