Also you somehow see to confuse moral and ethical. Moral is "Eww, that's itchy." For example sodomy. Ethics are a reflection and systematization of the first. The latter is abstract.
There are no universal ethics. But several sound systems. Kant's Categorical imperative, several utilitarianism. Hell even Hedonism is ethics and IMO a way better than morals.
But all these have in common they do give explanations and justifications, unlike morals. Morals is just "that's nothing one should do" or "We never did that." And I can't see a ethics that would demand the criminalization of public nudity. However it is very easy to reduce to criminalization of killing and theft to a sound first principle. And IMO only these first principles are important enough to force them upon others.
Killing someone derives them or life, theft of a possession, beating an animal hurts the animal.
Public Nudity may not be comfortable to you but what's the consequence beyond that?
So are laws against killing people, theft, and beating animals.
I'm always dismayed at people who think that the "good" ethical norms that they like are somehow scientific, universally agreed upon, and absolute, whereas the "bad" ethical norms that other people have are merely cultural, subjective, and contingent.
We could do worse than to require a few years of ethical theory as a precondition to graduating high school.