Why doesn't Bob sleep with her? We keep expecting it to happen. By the end of the movie even Charlotte, clearly, expects it to happen. It is not that he is too good a man to cheat on his wife. Sofia Coppola removes that explanation for us by showing him taking the bar singer to bed.
He is not the worst sort of man. He loves his children. He is going to return to his wife and family.
So why doesn't he sleep with Charlotte? That is the mystery the film begs us to solve. One reason is that he cares for her. The bar singer he can't hurt by taking to bed, but Charlotte he can. He is not very noble, but noble enough not to do that to her in exchange for a brief pleasure he can have, and has had, with so many other women.
But there is that other reason too. Right now, Charlotte is special. She has been a portal for him into a better world, a world of possibility, a world where love might be real and lasting. To sleep with her, on the other hand, would be to make her like every other woman in his life, girl number 25, and counting.
It is only by not sleeping with her, by not reducing her to an object of use, that she can remain to him singular, special and real.
And so it is a love story, after all.
Maggie Gallagher is a nationally syndicated columnist, a leading voice in the new marriage movement and co-author of The Case for Marriage: Why Married People Are Happier, Healthier, and Better Off Financially.