Tricks of the Trade (1968)

Fred and Salina Claret have been married for five years, but their marriage is on the rocks. Salina's interfering and domineering mother, Minnie, creates tension while Fred's sexual interest in Salina is foundering. In a bar in Greenwich Village, Fred meets Marcy and Stud Perkins, a swinging couple who invite Fred back to their apartment to smoke pot and have a sexual threesome. The next day, Fred visits his psychiatrist, Pauline Flood, to discuss his marital difficulties and confides in her about his infidelity. Dr. Flood obviously has a strong sexual interest in Fred. Meanwhile, Stud and Marcy plot with their friends to blackmail Fred for $5,000 with incriminating photos that were taken of him during their encounter. When Salina suspects Fred of cheating on her, she attempts to follow him, but gets attacked by two degenerate street derelicts, while Fred has a fateful confrontation with Stud and Marcy at a sex orgy.