Hurra, unsere Eltern sind nicht da (1970)

The parents have won a trip to Mallorca. Shortly after the Müllers leave, their nanny Kitty decides it is finally time to become a singing star and model, and quits, leaving the four children—the teenager Babsi, the twins Max and Moritz, and the little boy—with the house to themselves for once. Their older brother Klaus, a civil engineer specializing in underground construction, is supposed to look after them, but he is often at work. The children and Klaus quickly take a liking to Irene, the new lodger, although Klaus’s past increasingly catches up with him: not only is he involved with Silvia, but numerous former admirers approach him when he shows up at the disco with Irene. After Irene once again sees Klaus kissing Silvia, she angrily moves out of the Müller apartment. In the meantime, the children have found a devoted babysitter in their Uncle Alois, who is also inclined toward modern methods of child-rearing: a child should never be forced to do anything or given orders by their guardian. Instead, the music teacher introduces family music-making for everyone, much to the dismay of the landlady Emma, whose good-natured husband Gustav is under her thumb. After Emma has already drawn up an eviction notice for the Müller family, Alois manages to win Gustav over. With a simple trick, Gustav becomes the dominant head of the household and puts his endlessly chatty, nagging wife in her place. With a little luck and diplomacy, Gustav manages to reconcile Irene and Klaus. Everyone comes together again on the twins’ birthday: the parents return early from their holiday so they can celebrate with them, Kitty has given up her ambition to become a model and singer and starts working as a nanny again, Irene and Klaus announce that they plan to marry, and Alois is getting married too: he has fallen in love with Asta Kolle, a resident of the house.