The thesis is that sexual relations between patient and therapist are not best described by the concept of boundary violations. In fact, boundary violations typically do not result in the pain and trauma that is so characteristic of sexual relationships between patient and therapist. It is argued that sexual relationships are fundamentally a different kind of transgression from those that can be captured solely by “boundary violation.” It is in the very nature of analytic therapy that the therapist makes a commitment to treat all of the patient's communications as expressions containing meanings that were intended. When a sexual relationship takes place between the analytic pair, that promise is broken, and the analytic space collapses, leading to pain and often trauma. The argument is made that this collapse of the analytic space is the essential quality of the trauma in sexual relations between patient and therapist, not boundary violations. This thesis is illustrated with a case treated in analytic therapy.