Taboo (1980)

Scott, Barbara's husband, leaves her, blaming her for frigidity and the destruction of their marriage. The woman is left completely alone. In addition, she now has to earn a living herself and raise a teenage son. Barbara turns to her friend Gina, who introduces her to the secret world of suburban swingers. And everything would be fine, but sexual tension grows and fantasies about a handsome son become more and more desirable.