The siblings Sieglinde and Siegmund von Arnstatt are inseparable. Their arrogant manner is particularly felt by Sieglinde's fiancé, Lieutenant Justus von Beckerath. Siegmund jealously watches over his sister, with whom he falls into a frenzy of emotion during a performance of Richard Wagner's opera "Die Walküre." Beckerath realizes that he will never be able to break into the incestuous intimacy of the twins. Finally, Siegmund and Sieglinde give themselves over completely to their sensual intoxication...

Angela and Robert have been married for ten years and make a perfect couple. They are madly in love with each other, give each other plenty of space and support each other in everyday life. This idyll is put to the test when Robert's girlfriend Claudia moves in with the couple and Angela falls in love with another man. According to a mutual agreement between Angela and Robert, anything goes if one of them breaks their promise never to leave the other.