Life, that's what. [She tells him that in a very definite tone, like that's the greatest wisdom in the world.]

People die. I'm dying. Wha'd you say again? Mass of dying cells?

An' you're a faker. [She pokes him in the chest, rougher than she normally would have.] 'cause when you finally stop being all scared'a me, I'll be like that really boring Kansas song. I'm gonna die an' leave you all alone with your brother. He wins.

[Can you venture a guess who she's been talking to?]