...without major, perhaps not initially predicatable changes,
I do not believe that government has a direct interest in matters of sexual morality. I agree, however, with Aristotle and others who say that a democratic polity rests on its middle class, defined as much as anything else by its "bourgeois virtues." Excise the sexual virtues from the matrix, and the others will be affected, as we have seen happening during the last two or so generations, if not more.
[A later posting of mine expands on that theme.]