Pedro Romero is the great hope of this novel. Sure, you might scoff, being a beacon of hope in a hopeless novel like The Sun Also Rises is easy-peasy. After all, pretty much everything is more hopeful than the lives these dudes lead.
But Romero is something more. He preserves a kind of instinctive sense of honor and purity that Jake and Montoya recognize as the mark of the true bull-fighter:
Romero never made any contortions, always it was straight and pure and natural in line. [...] Romero’s bull-fighting gave real emotion, because he kept the absolute purity of line in his movements and always quietly and calmly let the horns pass him close each time. He did not have to emphasize their closeness. (15.52)
Brett is also drawn to him, but her admiration is both spiritual (she also recognizes his talent) and sexual (he looks hawt in tight matador pants).
Unlike Mike, Jake, Bill, and Cohn, Romero is young and virile; at nineteen, he is too young to be damaged physically or psychologically by the war, since he was only thirteen when it ended. Romero is a symbol of all that is still healthy and good in the world—he is totally dedicated to his craft, and he loves it more than life itself. Awww.
However, the introduction of Brett into his world throws all of this into question. Everyone disapproves of the Brett-Romero tryst, and people start to view Romero as more than a little seedy. As a result, Jake, who is culpable in the affair of Brett and Romero, feels incredibly guilty for endangering everything Jake, a true aficionado, holds sacred.Pedro Romero Timeline