Voodoo Passion (1977) [Blu-ray]

Susan, who arrives in Haiti to live with her new husband Jack, who has an apparently unhealthy, possibly incestuous relationship with his sister Olga. Getting lost in a fever dream of sexual delirium, Susan suddenly finds herself lost in a weird world of black magic, clandestine couplings and bloody voodoo rituals, all the while her possibly sinister housekeeper looks on lustfully.