The Wall of Flesh (1968)

Vera, a working woman, punishes her husband Art, a struggling writer who lives on her income, by denying him sexual satisfaction. While Vera is away at work, Art becomes involved with two sisters, Nan and Lauri. Aware of the strong physical attraction between her sister and Art, Lauri suppresses her own desire for the writer and arranges for her sister to be with Art by persuading Vera, apparently frigid, to attend group therapy sessions run by her ex-school friend Jennifer, a lesbian. Art however, rejects Nan's obvious advances, unaware that by this time his wife, seemingly happier, has been drawn into lesbianism. In a weak moment, though, Art gives in to Lauri (also a participant in Jennifer's group); but, still in love with his wife, he resists proposal to run away together. Lauri senses that her sister is heading for a breakdown over Art and she sacrifices her own ambivalent feelings for him to bring the two together. Art and Nan are finally united when Art lands a job in Chicago and finds that his wife prefers to remain with Jennifer, Lauri and the group rather than go with him.