"When do girls get these things?"
"Um ... well," I said, keeping a straight face, "Eleven or twelve or ... thirteen. When they start to become teenagers."
"Huh." He climbed into bed. "What about boys?"
"Well ... boys don't get them. They're called breasts." (In for a penny, in for a pound, I figured. Might as well give him some accurate information.) "You know how everyone is shaped differently?" I said.
"Well, some girls have little breasts, and some girls have bigger breasts," I said diplomatically. "Because we're all different."
"Oh." He regarded my breasts. "I think you're medium-size."
Wow. I've never been medium-size before!!! What a thrill!