Claude Mulot - Les Petites écolières AKA Little Schoolgirls (1980)

Synopsis
Brigitte Lahaie runs a whorehouse that is raided by the cops again. The raid interrupts hooker Marilyn Jess's session with a transvestite politician. When he is led away she returns to her magazine with a perfect bored pout on her face. The policeman in charge suggests, ironically, that Brigitte runs a school. So she opens a school for sex for young ladies, teaching the lessons herself and employing Alban Ceray and Dominique Aveline as tutors/demonstrators. Four girls enroll. She sells tickets for the graduation cermeony where the students demonstrate their newly acquired skills in a series of hard core mini-plays on stage. Brigitte performs too, with the winner of a raffle among the audience. Then the establishment is raided yet again.