I'm an Italian son of Noah.
In the Italian legal system, as I believe in many other countries, in addition to divorce there is the legal separation between the spouses. According to the Italian law with legal separation, which is a prerequisite for divorce, for both spouses the obligation of cohabitation and the obligation of reciprocal fidelity are extinguished:that is to say, they can legally have sex with other people, although the spouses are still married because they have not yet divorced.
In Italy legal separation between spouses is preliminary to divorce, but does not oblige spouses to divorce later, and in fact it happens that several married couples remain legally separated without divorcing.
According to the Halakhah, under what circumstances a married couple of Gentiles is considered divorced,regardless of what is established by the Laws of the Nations?