Casey finds her room in the new house too small to live in so she manifests her dissatisfaction with the parents. It turns out in a battle between the two "step" siblings to determine who will have Derek's room.

Casey and Derek are left alone for the weekend, but Derek throws an outrageous party.

Casey plays wedding planner for her aunt's wedding, having to put up with her annoying new step-brother and her equally annoying cousin. Derek gets put in charge of the wedding video.

Nora and George need a babysitter for an upcoming day trip and Derek ends up being left in charge of Marti who has fun terrorizing him as he tries to impress the new girl from school, Sandra.

Casey seeks more organization within the McDonald-Venturi household.