I recommend The Lover's Dictionary. 
 livid, adj. 
 Fuck You for cheating on me. Fuck you for reducing it to the word cheating. As if this were a card game, and you sneaked a look at my hand. Who came up with the term cheating, anyway? A cheater, I imagine. Someone who thought liar was too harsh. Someone who thought devastator was too emotional. 
 UNFORGETTABLE. 
 The Lover's Dictionary turned me into this mushy lil marshmallow. I felt a lot of emotions when reading this: i smiled a lot because i can relate. i harbored resentment when trust was broken. i felt complete when despite the frustrating times, the couple worked out their differences. Truly, The Lover's Dictionary is a haven for hopeless romantics! 
 I love how Levithan presented his story - through snippets of the couple's lives encased in vocabulary words. I basically have to read between the lines and i loved that. This kind of storytelling was so unique and effective it made me think: a word can really have a whole lot of meaning, right? Arrears. Dumbfounded. Libidinous. 
 The Lover's Dictionary is a quick read (211 pgs) but the writing will stay with me for a very, very long time. If you're in a mature relationship who needs guidance, or you just can't resist a romantic read, try this Levithan book. It sure made me sigh and realize how wonderful it is to have someone to love... and love me back that much. =) 
 Special thanks to Tina for lending me her copy while we were on vacation!