My Wife Understands Me (1959)

A literature professor (Arturo de Córdova), single and shy, has lived in love with the wife (Marga López) of his best friend (Armando Calvo), who is unfaithful to her. Every year's end he celebrates alone, toasting in front of the portrait of his beloved. Due to a mix-up, the woman discovers in a coat a letter from her husband's lover, a frivolous star called "Ardilla" (Lilia Prado). The professor makes her believe that the garment was his, thus creating a mythical personality of an ardent lover among his students. And the sensitive daughter (Martha Mijares) of the couple believes by mistake that there is a relationship between her mother and the professor.