Constitutive of the prevalent sexual morality in most Western European countries is the liberal principle of mutual consent (PMC). This sociological fact may give rise to the ethical question as to whether or not the state has the right to make sure that its citizens will observe PMC, among other ways by prescribing some form of sex education which has PMC as its moral content. With reference to the ambiguity of the term "morally permissible", it is argued that PMC can be interpreted in two fundamentally different ways, namely, as the freedom to arrange one's sexual life according to one's own values and preferences (PMC(a)) or as the view that consensual sex is morally all right or morally unobjectionable (PMC(b)). The claim is defended that PMC(a) should be taken as part of the public morality, whereas PMC(b) should be seen as a private morality. Accordingly, the state has the right to take PMC(a) as a basis for its educational policy, but the state is not allowed to prescribe any form of sex education that has PMC(b) as its moral content. The importance of the distinction between PMC(a) and PMC(b) is shown by giving an evaluation of the Dutch state's responses to recent public statements of orthodox religious leaders about the moral status of homosexuality. Also on the basis of this distinction, the central differences between liberal orthodox and fundamentalist orthodox religious views on sexuality and the role of the state are pointed out. In this connection, it is argued that any view which takes PMC(b) as part of the public morality should be disavowed as a kind of "liberal fundamentalism".