Compersion is an important concept for non-monogamous people. Often described as jealousy's opposite, compersion labels positive feelings toward the intimacy of a beloved with other people. Since many people think jealousy is ordinary, intransigent, and even appropriate, compersion can seem psychologically and ethically dubious. I make the case for compersion, arguing it focuses on the flourishing of others and is thus not akin to pride, vicarious enjoyment, or masochistic pleasure. People cultivate compersion by softening their propensity to be jealous and by attending to the flourishing of others, which requires them to tackle entitlement and temper vulnerability. I argue that jealousy is not a valuable emotional disposition; its instrumental benefits are minor, unstable, and have to be traded against the harms of aggression. Arguments that conclude that jealousy is a virtue rest on contentious premises and overlook the practical question as to whether jealousy and compersion could be cultivated together.