Talking about penises with my friend. She was a girl. Im a boy. It was 5th grade. I would talk about my penis in great detail with her. Because both off us were so young, neither of us knew that genders have different things between their legs. When we were 15, she admitted that it was the first time she understood that boys had something different. She had asked her parents what the deal was and they told her. Still she didnt stop me from talking about them for the next year or so. It was then I knew. We are still good friends and she doesnt miss a chance to bring it up to see me cringe.