A Drop of What?

Overheard at our house...
Mommy: There's blood on your neck. What did you do?
Blond Twin: I don't know. Where is it?
Mommy:  On your neck, right here.
Blond Twin: How did I get blood on my neck?
Mommy:  I don't know. Go wash your neck and let's see.
Blond Twin: Oh, it's not blood. It's pizza sauce.
Mommy looks at the Brunette Twin and sighs. Daddy laughs.
Mommy:  This is going on the blog.
Blond Twin:  I know.