Just read the bio of the lyricist, John La Touche. This song is from "The Golden Apple," a musical taken from parts of the Odyssey and the Iliad (yeah, I know!) This song is sung by Helen to seduce Paris. And the rest is...not history but myth. Such a great combination of lyric and melody (by Jerome Moross). Unforgettable and there is no comparison in the Great American Song Book.
Shirley Horn has a nice version of this too, and I know many prefer it. But her singing is so slow it becomes almost more a poetry recitation than a song. I lose the lovely melody. Lucy for my money nails it here.