The Dog in the Manger (1978)

Teodoro, secretary of Countess Diana de Bellefleur, looks after Marcela, the Countess's maid. Watching the development of their romance, the mistress suddenly feels jealousy awaken in her. But convention and the burden of prejudice have a strong hold over the independent and willful Diana. She, making fun of her noble suitors, cannot deign to confess her love to a rootless servant.