Why?

Jaeda: Whatchu lookin for?
Mum: I'm looking for a dustbin.
Jaeda: DUUSTbin? Why.. why you lookin for dustbin?
Mum: So I can throw my cup!
Jaeda: Why you wanna throw cup for?
Mum: Because I've finished my drink already, Jaeda.
Jaeda: Why, why you finish your drink for?
Mum: -__-
Jaeda: You wait here. I get more drink for you.