Death In A French Garden - 1985 - 6/10
AKA - Péril en la Demeure

Unemployed male catnip becomes guitar tutor to daughter of affluent parents.
The wife initiates an affair almost immediately.
In the cafe, his female neighbor talks suggestively of differences between the brunette bush and the blonde bush.
Also, in the cafe, the waitress leans forward (twice) to display swaying charms.
Did I mention his pupil was a rich daughter? Does she want him also? Ha, silly.
For all that, this is not a sex comedy.
Surveillance VHS tapes appear, suggesting blackmail.
Really, don’t people, even adulterers, bother with curtains?
Tone steadily darkens (reference title) as traps from various partners snap down.