The Lover's Dictionary by David Levithan

An entire book, the story of a relationship, told in dictionary entries.  Good stuff.  Fun stuff.  Heart-rending, easy-to-identify-with stuff. 

A few entries:

commonplace, adj.
It swings both ways, really.

I'll see your hat on the table and I'll feel such longing for you, even if you're only in the other room.  If I know you aren't looking, I'll hold the green wool up to my face, inhale that echo of your shampoo and the cold air from outside.

But then I'll walk into the bathroom and find you've forgotten to put the cap back on the toothpaste again, and it will be this splinter that I just keep stepping on. 

only, adj.
That's the dilemma, isn't it?  When you're single, there's the sadness and joy of only me.  And when you're paired, there's the sadness and joy of only you.

recant, v.
I want to take back at least half of the "I love you"s, because I didn't mean them as much as the other ones.  I want to take back the book of artsy photos I gave you, because you didn't get it and said it was hipster trash.  I want to take back what I said about you being an emotional zombie.  I want to take back the time I called you "honey" in front of your sister and you looked like I had just shown you pictures of us having sex.  I want to take the wineglass I broke when I was mad, because it was a nice wineglass and the argument would have ended anyway.  I want to take back the time we had sex in a rent-a-car, not because I feel bad about the people who got the car after us, but because it was massively uncomfortable.  I want to take back the trust I had while you were away in Austin.  I want to take back the time I said you were a genius, because I was being sarcastic and I should have just said you'd hurt my feelings.  I want to take back the secrets I told you so I can decide how whether to tell them to you again.  I want to take back the piece of me that lies in you, to see if I truly miss it.  I want to take back at least half the "I love you"s, because it feels safer that way.