The Ideal Marriage (1968)

The 1st of 2 Franz Josef Gottlieb films supposedly based on the works of Dutch gynecologist Van de Velde. A precursor to the more popular Schoolgirl Report pseudo-documentaries the Gottlieb "Van de Velde" films tried to take a scientific approach to various sexual discoveries within relationships. Taking the documentary route would allow Gottlieb (and other director's of the time) to introduce more graphic and risqué subject matter that was normally not shown in Germany during this time period.