As I was about to get into the shower:
Jenna: Mommy, your panties are up your butt.
Mommy: I know.
Jenna: Do you want me to pull them out?
Mommy: No. It's okay, they're supposed to be in my butt.
Mommy: Because it's something called a 'thong.'
Jenna: Can I wear one?
Mommy: Not right now, but when you're a grown up you can.
Jenna: When I'm five?
Mommy: Um, NO. When you're old.
Jenna: When I'm 100?
Mommy: No, that's TOO old.