Scandalous Photos (1979)

Juliette, an ex-prostitute whose two passions in life are men and money. When she isn't indulging in steamy sex sessions, Juliette and her lover Chris plan to blackmail young heiresses by photographing them in highly compromising situations, and their task is abetted when Juliette's sister Diana - who works as a high-class hooker - gives the couple a list of the daughters of wealthy businessmen who are looking for a bit of rough.