If there is a baseline principle of generally accepted public morality in the modern world it is the importance of willful consent. Without consent, nothing is ethical. While consent has never been a panacea and we have always recognized circumstances and classes of relationships wherein it is unacceptable or impossible to proffer consent, in general two consenting adult's behavior must be accepted so long as they generally limit the circle of consequences of such consent to themselves and not to others who have had no opportunity to proffer consent. Note that the most universally accepted classes of consent limitations are the consequence of recognized power differentials (i.e. an otherwise acceptable relationship between two consenting adults may be deemed ethically inappropriate if one of them is the supervisor of the other). The nature of this limitation indicates that the truth underlying the ethical system is a recognition of the functioning of power differentials; or, to put it another way, the functioning of power differentials is inherently primary whereas consent is a secondary consideration. Again, regardless of how one perceives ones internal motivations, the system is premised on a recognition of power differentials which perceives that there are situations in which consent is functionally impossible. The system focuses on the ethicality of consent because of the perceived value that this bestows on the actor proffering the consent--that is, part of the value inherent in the human person is that they are a being capable of proffering willful choice. It expresses an ideal hope that human persons have concerning themselves--that at our best, we are autonomous willing units employing our power of free choice. There is much truth in the power of this hope, but I wish to suggest that while such willful freedom is both conceptually and actually possible, it is never actualizable based on the strength of the willing person, but only realizes itself in moments of what we may call "grace" whereby circumstances have aligned themselves such as to allow for a "moment" of purely free choice. Thus, consent in any real sense is functionally impossible, because free will is not "willfully" actualizable. This unveils the "noble lie" of our governmental order, for consent underlies neither the morality of actions between persons nor can it functionally legitimize a governmental system whereby "just powers derive from the consent of the governed". Don't misunderstand me, it is a very good lie in that it tends to confuse both the governed and those who govern. But the true basis for the legitimization of our governing order must lie elsewhere, and the basis for the morality of our interactions with one another must lie elsewhere.
[Postscript: at its best, the concept of consent serves as a conceptual/legal limitation on the powers of the state/powerful over the lives of those with less power. Thus it serves a useful function. But it is functionally a legal fiction which we have come to mistake for an ontologically valid criterion of human interaction. If only the law could exist without creating its own tautology!]