Which book are you reading?
"The Spanish Bourbons" by John D. Bergamini.
I've never really paid close attention to present day dynastic claims disputes and I'll have to get to the end of the book to see what the Spanish Carlist pretenders are doing right now. Up until Alfonso XII, the Carlist line appears to have kept the Bourbon Y chromosome. With Alfonso XII, there is doubt as to whether his father was actually the allegedly gay Francisco of Asis, the Bourbon first cousin of Isabell II. But even if he was, there is still a question as to whether Francisco of Asis' father, the Infante Francisco, was the illegitimate son of Manuel Godoy and Queen Maria Luisa, wife of the cuckolded Carlos IV.
In Goya's "Family of Carlos IV", the Infante Francisco, alleged illigitimate son of Manual Godoy, is the male child holding Queen Maria Luisa's left hand. The future Fernando VII, who produced no male heirs and was the father of the sexually adventurous future Queen Isabel II who marrried her uncle Fransico's allegedly gay son, is the teenager dressed in blue on the left hand side and his brother, the Infante Carlos, is the younger boy behind him.
Unless I missed something in prior chapters, by the 1870's when the Bourbon Spanish throne was restored in the person of Alfonso XII, Isabel II's son, only the descendants of the Infante Carlos, the son of King Carlos IV, could unquestionably claim male descent directly from Louis XIV.
