> This is why we have a justice system, so that there is one place where you can say "that is wrong" and "that is right".

In most (all?) Western countries, cheating on your spouse is not illegal. But 99% of the people would say that "it is wrong".

Adultery is a crime in 16 US states: https://en.wikipedia.org/wiki/Adultery_laws#United_States

These are probably the only exceptions.