I love philosophy, and though I don't read much Plato these days--Friedrich Nietzsche is now my poison of choice--I still like to re-read the Symposium dialogue, which is the best dating and relationship advice anyone could ever hope for. It examines the ethics of love and desire, and explains why being sexy isn't necessarily a good thing.

A base man is that common lover who loves the body rather than the soul; for he is not lasting since he loves a thing not lasting. For as soon as the flower of the body fades, which is what he loved, 'He takes to the wing and away he flies,' and violates any number of vows and promises; but the lover of good character remains faithful throughout life, since he has been fused with a lasting thing.