Successive Slidings of Pleasure

The erotomaniac girl in this French film likes to tie her boyfriend up and make love to him. She also likes to cover herself with various unlikely unguents and make love to him. On one occasion, after she has tied him up but before she can return to him covered in raw egg and paint, someone slipped in and stabbed him to death with a pair of scissors. Naturally, she is the principal suspect in the killing.