The recent #metoo movement has turned public attention to the problem of sex under conditions of power inequality. Is consent impaired, when you have plenty to lose (e.g. a great professional opportunity) from saying “no” to a sexual advance? And even if consent is valid, is this a morally acceptable situation, especially if one party is aware that their position of relative power will influence the other’s decision to have sex? Such situations bring to the fore not only the issues (...) of coerced sex and quid pro quo harassment (asking for sex in exchange for benefits), but the much more controversial question of whether sex between unequal but otherwise competent consenting adult partners is in principle OK—and whether institutions such as companies, universities, or the state itself should be in the business of regulating such relations. In what follows, I will outline the central concept of power asymmetry and its ethical relevance (section 2). I will then distinguish two main views about the ethics of sexual interaction under conditions of power asymmetry: a Kantian view, which categorically condemns such interactions, and a Millian view, which justifies at least some such interactions (section 3). I then briefly consider three contexts, which raise difficult questions about sex between unequals: the workplace, the university (section 4), and voluntary prostitution (section 5). Section 6 provides a short conclusion. (shrink)