As head of the household while his parents are away for the weekend, an overly confident Alex throws a big bash, but when his sister Mallory leaves the party with the school Romeo, he's filled with guilt and anger. A little wary about leaving the kids alone for the first time, Steven and Elyse finally depart for a weekend with their friends, the Davis's. While the romantic holiday turns into a marathon sports competition instigated by Ron Davis and resented by Elyse, there's trouble brewing on the home front. Teenage brother and sister clash when Alex assumed the attitude of an overprotective father and lectures Mallory for arriving home late from her date with sports hero/lothario Eric Morrison. However, when Eric arrives at the Keaton doorstep with flowers to apologize, it's clear that Alex has jumped to a false conclusion. He must now restore peace and tranquility by the time his parents return home.