Offspring Story of the Day

Ahh, unclear on the concept... :)

Me: Knock, knock.
Mags: Who's there?
Me: Boo.
Mags: Boo who?
Me: Its ok, don't cry!
Mags: Hahahaha! Ok, my turn! Knock, knock!
Me: Who's there?
Mags: Grape!
Me: Grape who?
Mags: Boo hoo! Hahahahaha!
Me: (laughs)
Mags: Ok, here's another one! Knock, knock!
Me: Who's there?
Mags: Boo!
Me: (thinking she's actually got it this time) Boo who?
Mags: BOO! Hahahahaha!