Nakedness and Sex

Tonight was bath night at my house. Jack, my nine year old, was dressed in his pajamas after his shower. Julia, my six year old, was lollygagging, as usual...putting off the inevitable shower. Finally, she got undressed.
Jack was teasing her about something so she walked up to Jack and stuck her naked butt into his space. That's when the conversation began...

Jack: Julia quit sexing me.

Mom: Jack, did you just say sexing?

Jack: Yeah. Why?

Mom: What exactly do you know about sex?

Jack: I know what it is. It's when two people get naked and rub their butts together.

Let's just say, I got ready for the sex talk pretty fast. Not something I planned on talking about, but I guess I have to stay ahead of the kids on the bus who I am sure shared this lovely tidbit of information with my third grader.