Auf der Heidi gibt's koa Sünd' (1990)

In a small mountain village, secluded from the world, Heidi, well looked after by her grandfather, has grown up to be a strapping little girl. One day, her aunt Grete arrives from Munich to give her a "proper upbringing". But Heidi becomes engaged to Ziegen-Willi and has her first experiences with him and the male sex. Things are generally lively and frivolous in the mountain village...