When Susan Sontag was twenty-seven, she wrote in her journal about a feeling that had no name. X, she called it; people and things could be X-y. She defined it variously as “the compulsion to be what the other person wants,” “the scourge,” and “when you feel yourself an object, not a subject.” Sontag identified the source of X as this: “I don’t know my own feelings.”

Katherine Angel, in her 2012 book Unmastered, uses Sontag’s concept of X to try to describe what she herself finds difficult to pin down in her own sex life. X comes to denote that part of one’s sexual desire that is contingent