A journalist sets out to expose a female sex expert but falls for her instead.

Bob Weston, managing editor of scandal magazine Dirt , writes a sensational and highly successful article on research psychologist Helen Gurley Brown, whose recently published book, Sex and the Single Girl , has become a national bestseller. Bob is assigned to interview Dr. Brown, but she refuses to see him. In order to meet her, Bob impersonates one of his neighbors, Frank Broderick, and goes to Helen for marriage counsel. After several meetings, during which Bob suggests to Helen that they commence an affair, he telephones her and threatens to drown himself unless she capitulates. She rushes to him and accidentally causes them to tumble into a boat basin. They go to Helen's apartment to dry out; Bob mixes a potent batch of martinis and attempts to seduce her. Helen confesses her love for Bob, and he replies that all is well; he is not legally married. Helen doesn't believe him and asks to see Sylvia, his wife. The next day, Bob inadvertently sends both his secretary, Susan, and his former girl friend, Gretchen, to Helen to impersonate Sylvia and convince Helen of his claim. Helen summons the real Sylvia, and the three women all turn up for the appointment. Sylvia has Frank jailed for bigamy; Helen deduces Bob's ruse and decides to leave town with colleague Rudy DeMeyer; Bob is fired from Dirt when he refuses to slander the innocent doctor by his article. He follows Helen onto the San Diego Freeway where they encounter both Frank, who is trying to escape to Hawaii, and Sylvia, who is pursuing him in a cab. After a wild chase and a hectic mix-up at the airport, the couples all get sorted out: Frank and Sylvia become reconciled, Bob and Helen get together at last, and Rudy and Gretchen unexpectedly enplane for Hawaii.