Secrets of a Chambermaid (1998)

aka Madame Felicity's Erben · Les secrets d'une femme de chambre · Los secretos de una mucama

In this erotically-charged drama, four people are gathered at a secluded mansion to hear the reading of will of the late Aunt Felicity Kendall. The guests are advised that the reading is postponed and will learn which of the four will receive the full estate later in the weekend. As the days pass, they find it impossible to curb their sexual appetites. What they don't know is that their bedroom activities are being observed, and that there's more to this gathering than they've been led to believe.