Here is how you know if it is love or lust. Push them in front of a bus. If you jump in the way and save them it is love.
Good morning, Eeyore," said Pooh. "Good morning, Pooh Bear," said Eeyore gloomily. "If it is a good morning, which I doubt," said he. "Why, what's the matter?" "Nothing, Pooh Bear, nothing. We can't all, and some of us don't. That's all there is to it. " "Can't all what?" said Pooh, rubbing his nose. "Gaiety. Song-and-dance. Here we go round the mulberry bush.