" If desire were really one to one, self to self, there would never be a problem of infidelity, but desire will always, without confusion, demand a particular class, Caring for a unique object is an illusion, but the feeling must be unique, and though that feeling may not be natural, it is duty. You must love your neighbour like yourself, uniquely. From the personal point of view, sexual desire, because of its impersonal and unchanging character, is a comic contradiction. The relation between every pair of lovers is unique, but in bet they can only do what all mammals do. All the relation in friendship a relationship of spirit, can be unique. In sexual relationship love the only uniqueness can be fidelity. "

― W.H. Auden , Lectures on Shakespeare