My daughter's birthday was the other day. I have been trying to push Star Wars on my kids for years, and my now 5 year old daughter is actually accepting it better than my 7 year old boys. So this year we found a used Princess Leia Barbie-type doll for her. After playing with it for a few hours, my daughter peeked under her skirt. Noting that Leia wasn't wearing any panties, my daughter asked me, "Daddy, how come Leia isn't wearing any underwear?" I only barely resisted my immediate urge to respond, "There is no underwear in space."
It was hard having such a wonderful joke fall right into my lap and have no one to share it with. :( That's why I'm so glad I have all of you nerds to hang with. :)