The Story of O (1975) torrent

Before 50 Shades of Grey became the purified, Walt Disney version of a real lifestyle. (human trafficking and sex slaves exist still to this day)

From IMDB:

Rene takes his lover, the photographer O, to a manor in the isolated area of Roissy to be submitted to humiliations, bondage and sexual perversions to prove that she belongs to him. O spends several days being sexually abused by several men and whipped until she is ready to return to Rene. Then he shares O with his older step-brother Sir Stephen until Rene finally gives O to him. Meanwhile O and Sir Stephen fall in love with each other