Can anyone ID this German Film

[DavidS]

The film was made in about 1976 or 77. It concerned a family group made up of a father, mother, son and two daughters. The family had a maid who was responsible for waking the whole family up in the morning by various sexual means. The actresswho played the maid, had long raven hair, was slim and very attractive. The mother was played by an actress in her forties with red hair, a rubenesque figure and outstanding facial features. A birthday treat was arranged for the maid whereby the boyfriend of one of the daughters had anal sex with her, while the son and father had oral and vaginal sex, all at the same time. The two daughters had a number of boyfriends but none were allowed to see them until they had serviced the mother! The two daughters and the mother owned a launderette and had sex with all the male customers while they waited for their washing to be done. The birthday party part of the film was released on a Paradiso short and I have seen short excerpts from other parts of the film. I have never found out what the original was called or who made it. Any ideas?