How would you define sex to a 9yr old boy? The act of sex. He heard kids talking about porn at school and decided instead of asking me what it was he was going to look it up. But he was on YouTube so he didn't actually see sex like from a porno but he's curious about girls and them naked. And sex. I just don't know how far into "what is sex" should I go. I thought I still have a couple years to prepare for this talk. He just seems too young to me but I also don't want him learning it from kids at school.