With heterosexual transmission the chief cause of global HIV spread, those without the power to select sexual partners, choose the timing of sexual encounters, or insist on safer sex practices are unable to protect themselves from infection.
People have a social obligation to conform to the general rules of sleeping: sleep at night, in a bed, in a private place away from public view, and in proper attire.
Physicians make patients aware of those interventions that they (the patients) may then refuse. In short, informed consent is less about patient decisions than it is about restraining physicians.