Is prostitution wrong? Clearly, it's illegal in some countries. But is it really immoral or wrong? Surely prostitution may, in some limited set of cases at least, even maximize average utility, or involve consenting adults who agree to being used by one another, or one by the other, as "mere" means. What is the relevant difference, in principle, between a one night stand and an instance of prostitution? Or between paying for sex and paying for a cab-ride home for one's sex-partner after a one night stand (or paying for a meal or drinks beforehand)?