Desc: Mädchen mit offenen Lippen: Directed by Erwin C. Dietrich. With Rena Bergen, Nadine De Rangot, Libero Guidi, Herbert Kluever. At the girls' school, the young teacher requests the young women to prepare a lecture on the topic "The Preliminaries", for next week, before the year's end. The girls would contact him if they had any problems with their work. Thus a series of sexual experiments start, which will involve the whole class, and even the teacher.