Francisco Mega (Ribeirinho), a clerk at the then leading department stores of Lisbon, "Grandes Armazéns do Grandella", is in love with Tatão (Leonor Maia), who works in front at "Perfumaria da Moda". Tatão, however, is a cinephile who largely ignores him, whereas Francisco is also an amateur theatre player; so his amateur theatre company, the Grandellinhas, uses its rehearsals of the play O Pai Tirano (ou O Último dos Almeidas) to present Francisco as a son who split from his tyrant father for love, and woo Tatão.
O Pai Tirano offered a number of situations that became common reference in Portuguese culture.
Among them, a scene almost at the end of the movie, where one of the members of the theatre company, middle-aged Mr. Machado (a caricature of the don't-bother-couldn't-care-less Portuguese) takes his new girlfriend to dinner at the theatre buffet. To each request the lady makes, the item is unavailable, so they ask what she wants, and they repeatedly request "two glasses of white wine."
This line has since been used in adds for a Portuguese spirit.