One of the trickier subjects in fiction is that of the hapless suitor, besotted with love, locked in a lifelong obsession with a woman he can neither leave nor have. Yet, for all the perils of that soupy scenario, great literature has come of it. F. Scott Fitzgerald wrote memorably of just such a man in “The Great Gatsby”; William Styron, in “Sophie’s Choice”; Gabriel García Márquez, in “Love in the Time of Cholera”; and Mario Vargas Llosa, in “The Bad Girl.”