Servant and Mistress (1977)

When a rich man' dies and his maid Maria unexpectedly becomes his heir, she is now the mistress of the man's household. In order to get revenge on the man's nephew Jerome, for slights on her person which he committed while she was but a maid, she has kept him on as her personal valet. The two of them engage in a form of rivalry bordering on warfare, because the nephew thinks he should have gotten the money. However, every mean trick she plays on him makes her feel even worse, because he accepts them all without a qualm.