Greed
There are several greedy characters, and they all hang out in night clubs, which is fine except for their intentions are clearly to boisterously show off their wealth and privilege. This is especially true of Fontaine Khaled, because she didn't even earn the fortune she is spending; she married a wealthy man named Benjamin who made his fortune the hard way, with excellent business. At the end, when he finds out how she has spent his money greedily, she realizes that his business attitude extends to her too—he divorces her.
Broken romance
There is another problem with Fontaine's character. She views romance as a way of garnering social power and appeal for herself. She "empowers" herself by weakening the men she sleeps with, dragging her husband's name in the mud by cheating on him with people at the club—none of this bodes well for her opinions on romance. Also, Tony lets her abuse him and takes a predatory approach to wooing Alexandra, who plans a full blown romantic humiliation of him as punishment. The dark side of romance is shown in much variety.
Pride and humility
The book's central theme could be said to tie together the romantic misbehaviors of Fontaine, Alexandra, Tony, and Benjamin, along with the other themes, like greed and the lavish display of power; what do all these ideas have in common? They involve deliberate attempts to raise the character's pride. Fontaine finds nearly godlike power as the owner of her own nightclub. She can pretend for a moment that she isn't spending her husband's money, and suddenly, she feels like an absolute goddess. When she is broke and divorced, that is the end of this thematic portrait of hubris.
