Doctor Leo Marvin, an egotistical psychiatrist in New York City, is looking forward to his forthcoming appearance on a "Good Morning America" telecast during which he plans to brag about Baby Steps, his new book about emotional disorder theories in which he details his philosophy of treating mental patients and their phobias. Meanwhile, Bob Wiley is a recluse who is so afraid to leave his own apartment that he has to talk himself out the door. When Bob is pawned off on Leo by a psychiatrist colleague, Bob becomes attached to Leo. Leo finds Bob extremely annoying. When Leo accompanies his wife Fay, his daughter Anna, and his son Siggy to a peaceful New Hampshire lakeside cottage for a month-long vacation, Leo thinks he's been freed from Bob. Leo expects to mesmerize his family with his prowess as a brilliant husband and remarkable father who knows all there is to know about instructing his wife and raising his kids...

Its high school graduation, and like all seniors they want to party. So 500 high school seniors look forward to a party, while in the meantime a boy wants to get a girl he's loved for years that just broke up with her boyfriend and one head-case that wants revenge on a lifelong bully. So the party comes, things develop. People have sex, drink, and go along with most of the guidelines of a high school graduation party.