David is a young advertising executive on Madison Avenue in New York City, but when his actress girl friend, Sheila, gets work as a chorus girl in New Jersey, David quits his job. After a meeting with an Indian woman, he decides to expand his consciousness by selling his Porsche sports car, changing his condominium into a swinger’s pad and having sex with every girl he can. A few weeks later, Sheila returns to find the changes David has made and moves out. Later, David’s parents are visiting when his neighbor Carlos arrives with Reb, an African American female stripper who needs photographs for her Sadomasochism act. Carlos suggests David’s apartment is perfect for the photo shoot and David decides to frighten his parents. When Reb strips down to a latex outfit and straps David to his waterbed, his parents leave. David tells Reb to untie him, but she decides to use him for her photographs. She sends Carlos away and seduces David. The next day, Reb moves into David’s apartment and introduces him to her manager, Joey. After stripping at an American Legion hall, Reb takes David to a discothèque featuring the “Erotic Circus.” The place is packed with sexual deviants and the party turns into a riot when two drag queens get into a fight. David is hit by a bottle and Randy, Reb’s friend, helps carry him to safety. Later, after a bad reaction to mescaline, Randy, David and Reb have sex, unaware that Carlos is outside the window, filming. The next day, Sheila arrives with a birthday cake for David, but when she sees Randy, Reb and David sleeping off the night’s bacchanalia, she smashes the cake in David’s face. However, he does not wake up and Sheila runs out on the terrace, crying, only to learn from Carlos that his film proves David is bisexual. Skeptical, Sheila watches the film at Carlos’s apartment and prepares to have sex with him, until she realizes he is filming her. Sheila blows a rape whistle, which wakes up David in the neighboring apartment. He runs outside to find Carlos and Sheila fighting and tries to lie about Reb and Randy, but Sheila tells him Carlos filmed the whole thing. As Sheila gets in a cab, Carlos and David drag her out, but the female driver jumps out and threatens to beat Carlos in retaliation. Reb and Randy hurl pillows out of the apartment window. Soon a pillow fight ensues, ending when Carlos grabs Sheila and runs back inside, where Reb gets Sheila drunk to calm her down. Later, David informs Randy and Reb that his unemployment benefits end in two weeks and they will be out of money. Reba informs them they can make $10,000 if they film a soft-core pornographic movie. At a park, Reba lures a co-ed track team with a marijuana cigarette and leads the teenagers back to David’s apartment, where they all have sex as Carlos films. When the coach realizes her team is gone, she calls the police, who later find the teenagers hiding in a hot tub at David’s apartment. Chaos ensues and Carlos films as the police chase the nude teenagers over rooftops and down fire escapes. Later, David and Carlos realize they have enough footage for a movie and find a hideout to edit the film. Sheila brings them food and David convinces her to come to their premiere. The friends convene in front of an X-rated movie theater that is screening their film; dressed in business attire, they pretend to protest the film’s vulgarity to arouse public interest. Although no reporters appear, a psychotherapist, Vivian Hessel, arrives and hires the group to make films for patients with sexual problems. David convinces Sheila to quit her job, move back with him and make movies. Weeks later, Vivian transforms from an uptight professional to a marijuana-smoking libertine. She moves her eight-year-old daughter into David’s apartment, where all the adults are having sex. After a few months, Sheila announces she is pregnant and any of the men could be the father. The lovers decide to raise the family together and hold a group wedding. Years later, Vivian’s child, Kate, is a teenager and has twelve or more brothers and sisters from the group marriage. They form a band and give a rooftop rock concert for the neighborhood as David and Sheila looked on with pride.