A Funny Thing Happened on the Way to the Forum (1966)

Pseudolus (Zero Mostel), the laziest slave in Rome, has one wish: to purchase his freedom. When his master and mistress leave for the day, he finds out that the young master has fallen in love with a virgin in the house of Marcus Lycus (Phil Silvers), a slave dealer specializing in beautiful women. Pseudolus concocts a deal in which he will be freed if he can procure the girl for young Hero (Michael Crawford). Of course, it can't be that simple, and everything begins to go wrong.