Alfonso de Borbón y Borbón (1866-1934), President of the Spanish Red Cross and a younger son of Infante Sebastián (1811-1875), is alleged to have been briefly married to Julia Mendez y Morales. Spanish Wikipedia says they married in 1929, apparently citing Bouche, Luis Español (1999): Nuevos y viejos problemas en la Sucesión de la Corona Española. Madrid: Hidalguia. p. 70. However their marriage and divorce are actually mentioned in the 1923 edition of the Almanach de Gotha. Has anything come to light about this marriage, or about Julia's identity and her fate?
Side note: Alfonso made the record books for the insane number of Christian names he was given, which are listed in his otherwise anemic Spanish Wikipedia page.