The Zoey-Dustin sibling friendship (in fandom known as Zustin) is the pairing of Zoey Brooks and Dustin Brooks. Zoey always looks out for Dustin.
Episodes with a Zustin plot/subplot:
New Roomies - Dustin doesn't have any money, and Zoey tries to help him.
Defending Dustin - Zoey helps Dustin stand up to a bully named Keith Finch.
Bad Girl - Dustin starts dating a bad girl named Trisha Kirby, and Zoey tries to help Dustin by making them break up.