Tori: "Hey, Beck."
Beck: "Hey, Tori."
Tori: "Wanna do the alphabet?"
Beck: "Sure, why not?"
Tori: "A."
Beck: "B."
Tori: "C."
Beck: "D."
Tori: "E."
Beck: "F."
(This continues until Tori reaches "J", at which point she stops)
Tori: "Okay, I'm tired."
Beck: "What?! We only got to "F"!
Tori: "Yeah, but I'm tired."
Beck: "Fine, whatever."
The humor lies in the sudden and random ending, with Tori always getting bored before they make it through the entire alphabet. It's a simple but effective way to illustrate their playful banter and easy rapport.