– sunbathe topless on your own property or in the complete nude, but the latter only if nobody can see you.
– sunbathe topless on public beaches.
– be in the nude on nude beaches or at nude holiday resorts / camping sites.
– take pics of your children on the beach or in the tub if this clearly happens in all decency.
– display and view nipples and behinds on TV, in newspapers and on billboards.
You may not:
– completely expose yourself to unsuspecting strangers in person as well as through images.
– completely expose yourself to minors in person as well as through images.
– go streaking.
– (women) be topless at beach bars etc. unless it’s a clothing-optional place.
– enable minors to get hands on or watch pornography.
The aversion to public nudity, displays of affection and sexuality in the US that has found its extreme reflection in endless rules on tznius clothing and behaviour among Orthodox Jews is greatly influenced by Puritanism. Puritans in Europe would not have curtains in their windows so anybody could see they weren’t doing anything improper. Jokingly, people later assumed that this was so because Napoleon had levied a tax on curtains, but that is nothing but an urban legend. Judaism in Europe used to be pretty lax about nudity until it saw a need to cover up so not to provoke the increasingly prudish Christian environments, Protestant ascetics in particular. Nudes have always been a popular topic among Jewish artists, which in the early twentieth century CE resulted in the prejudice of Jews spreading pornography or being immoral. BTW, since I hear and read lots of incorrect assumptions about them, Catholic sexual morals are pretty much the same as Jewish ones and are even lenient on sexual intercourse during and after a woman’s period since it’s an expression of bonding in a relationship. So it may come as little surprise that particularly in those areas and cities were predominantly Jews and Catholics dwell, studies on sexuality frequently determine the highest rate of intercourse as well as the highest rate of people’s contentedness with their sex lives.
But we shouldn’t be bragging.