Shop Girl by Steve Martin.
This is one of my favorite books, and I had the urge to re-read it. Funny man Steve Martin is quite the writer.
The story of a millionaire, waiting for Ms. Right, and passing the time with Mirabelle the shop girl until she comes along. Mirabelle, of course, is in love. It's interesting to see both sides of the same relationship. Heartbreaking, but interesting.
Read it. And watch the movie. It makes me cry every time.