I haven't looked into this at all or seen anything.  The most I've seen was a video on Netflix about Taiwan Night Life.

They had a girl from the US who moved to Taiwan who ID's as a "them" (pronoun).  But does a drag show as a man.  Her daily life, she dresses as female. The drag club she was at seemed to have more foreigners there than citizens (haoles).  Which makes me wonder if US citizens who travel abroad are trying to change another countries views?  And do other countries look at the USA as crazy when they ID as "them" or even having to mention pronouns?

I am familiar with Taiwan and even that club.  It's in a night market that Mrs. CMO and I often visit.  It also has the closest restroom to the MRT (train) stop, which is why I know of the 'red building".  A few years ago, Taiwan legalized gay marriage.  So it is a little more common to see same sex couples holding hands in public while we were there. But the only couples we saw were  females.  We didn't see any dudes holding hands.

So I bring this up because people can soon put "X" as gender in their US passports. I wonder if they would not be allowed to enter another country due to this?  Then there's stuff in the fake news daily about pronouns and a tranny getting a job or some other related articles.

Most other countries seem to have less of a hangup with sex compared to the US.  It follows that they are also more tolerant of deviant/aberrant behaviors.

In Japan, men are expected to have a wife AND girlfriend/s as long as they are discreet -- based on a friend who's married to a Japanese national.  The ratio of girls to guys is about 5 to 3 last I checked.  Not enough guys to go around, so those who find themselves lucky enough to marry are tolerant of extramarital affairs as long as the family is looked after.  It's almost like a "duty" of wives to share their men with those who aren't able to find a single guy.

In many countries, prostitution is legal or heavily regulated. 

At the risk of getting "flamed".
The basis for most all our Modern western civilization sex hang ups is this
"Thou shall not commit adultery"  probably the shortest worded commandment of the ten commandments.
"The ancient Hebrews, in particular, had a very restricted understanding of the concept, limiting it to just sexual
intercourse between a man and a woman who was either already married or at least betrothed.
The marital status of the man was irrelevant. Thus, a married man was not guilty of “adultery” for
having sex with an unmarried, unbetrothed woman."

It seems most all cultures follow this rule and everything else goes.
There have been layers of restrictions added for cultural or practical reasons
eg. incest is BAD for the kids health.
But it always has been pretty much anything goes for the entire world.
USA's  pre-occupation with perversion is that the perverts expect
to be accepted as "Special" when they are not "normal" in a our society.
That is the friction.  Most everywhere else they keep it on the "Down low".
 




.

At the risk of getting "flamed".
The basis for most all our Modern western civilization sex hang ups is this
"Thou shall not commit adultery"  probably the shortest worded commandment of the ten commandments.
"The ancient Hebrews, in particular, had a very restricted understanding of the concept, limiting it to just sexual
intercourse between a man and a woman who was either already married or at least betrothed.
The marital status of the man was irrelevant. Thus, a married man was not guilty of “adultery” for
having sex with an unmarried, unbetrothed woman."

It seems most all cultures follow this rule and everything else goes.
There have been layers of restrictions added for cultural or practical reasons
eg. incest is BAD for the kids health.
But it always has been pretty much anything goes for the entire world.
USA's  pre-occupation with perversion is that the perverts expect
to be accepted as "Special" when they are not "normal" in a our society.
That is the friction.  Most everywhere else they keep it on the "Down low".
 
.

"Adultery" is having sexual relations with someone who's married to another (Extra-marital affair).

"Fornication" is having sexual relations with someone you are not married to or planning to marry.

In the times when the Commandments were written, as you said, a married man can have all the "concubines" he wanted if the women were not married.  That stems from the fact that women were deemed inferior to men.  Women were not expected to follow religious laws, because they just can't make those decisions for themselves.  They rely on the men in their lives to decide for them.

Still today, devout Muslim women are not allowed to drive, testify in court, etc.  According to the teachings, if a woman testifies, she will only repeat that which the last male that spoke to her told her to say.   

Our Christian and Puritan influences became the basis for our culture.  So, yes, the 10 commandments became the cornerstone of that culture.  Unfortunately, they didn't read past the Old Testament when making up the rules for our new nation.  Had they used the New Testament, they would have been good with one commandment:  "Do unto others as you would have them do unto you".  The sentiment is also derived from the same section (Sermon on the Mount) that says, "Love your neighbor as yourself."

Basically, Jesus was saying, don't do any harm to others that you would not want done to you.  It's a bit ambiguous and open-ended.