Les petites écolières (1980)

A madam runs a whorehouse that is raided by the cops again. The raid interrupts a hookers session with a transvestite politician. The policeman in charge suggests the madam, to run a school. So she opens a school for sex for young ladies, teaching the lessons herself and employing Lambert and Charles as male tutors/demonstrators. Four girls enroll. She sells tickets for the graduation ceremony where the students demonstrate their newly acquired skills in a series of hard core mini-plays on stage. The madam performs too, with the winner of a raffle among the audience. Then the establishment is raided yet again.