La adúltera (1975)

With more than thirty years, Malena Fonseca is a spinster and provincial woman who, after coincidentally meeting a Frenchman named Lucien, also a thirty-something bachelor like her, decides to marry him. However, after that, and having moved to Madrid in the company of her unbearable and possessive mother-in-law, Malena will gradually discover that her husband is a very rational man whose zero interest in sex despairs her, making the woman feel attracted to the pharmacist in the corner and the hunky bread delivery man.