“It is part of the nature of a strong erotic passion—as distinct from a transient fit of appetite—that makes more towering promises than any other emotion. No doubt all our desires makes promises, but not so impressively. To be in love involves the almost irresistible conviction that one will go on being in love until one dies, and that possession of the beloved will confer, not merely frequent ecstasies, but settled, fruitful, deep-rooted, lifelong happiness. Hence all seems to be at stake. If we miss this chance we shall have lived in vain. At the very thought of such a doom we sink into fathomless depths of self-pity.Unfortunately these promises are found often to be quite untrue. Every experienced adult knows this to be so as regards all erotic passions (except the one he himself is feeling at the moment). We discount the world-without-end pretensions of our friends’ amours easily enough. We know that such things sometimes last—and sometimes don’t. And when they do last, this is not because they promised at the outset to do so. When two people achieve lasting happiness, this is not solely because they are great lovers but because they are also—I must put it crudely—good people; controlled, loyal, fair-minded, mutually adaptable people.If we establish a “right to (sexual) happiness” which supersedes all the ordinary rules of behavior, we do so not because of what our passion shows itself to be in experience but because of what it professes to be while we are in the grip of it.”
C.S. Lewis