When Mona has Spencer masquerade as her beau at a friend's wedding, Spencer realizes that he has romantic feelings for her, and has had them since college. Meanwhile, Dee Dee dumps her boyfriend when she learns he has matrimony on the mind.

The gals' already tenuous friendship spirals toward dissolution when Dee Dee celebrates the end of her school year by hosting a raucous celebration that keeps Mona awake all night. Things get worse when Dee Dee installs a hot tub, which floods Mona's apartment. Stepping in to mediate, their father, Charles, reminds them that ""like it or not, we're family."" But the squabbling continues, until a medical emergency involving their dad arises.