Why did Colubmus not marry Beatriz?

This is the second film of that period in which the explorer had a faithful mistress. In Aguirre The Wrath of God, Don Pedro de Ursua, one of the conquistadors had a faithful mistress who came from a wealthy family, but he did not marry her. I know that the Spanish of that period were appalling snobs and treated the choice of a wife almost like purebred horses, and therefore would never under any circumstances marry someone who was not of the 'right' family and background, but Columbus was not Spanish and not a nobleman. I have heard that for a couple of centuries the Spanish in Mexico would seek husbands for their daughters in Spain rather than let them marry one born in Mexico, who they considered inferior.