La regenta.

Married to the retired magistrate of Vetusta, Ana Ozores cares deeply for her much older husband but feels stifled by the monotony of her life in the shabby and conservative provincial town. And when she embarks on a quest for fulfillment through religion and even adultery, a bitter struggle begins between a powerful priest and a would-be Don Juan for the passionate young woman’s body and soul. Scandalizing contemporary Spain when it was first published in 1885, with its searing critique of the Church and its frank treatment of sex, La Regenta is a compelling and witty depiction of the complacent and frivolous world of upper-class society. - Random House