Israel is betrothed to the Holy One, blessed be He; Israel is even His wife. G-d made Israel for Himself because he lacked a significant other in His life. The whole purpose of life is to find true and lasting happiness with someone of the opposite sex. But Israel was sent into exile because of its adultery - i.e. its worship of idols - and it has become even as a menstruous woman before His sight. But He has still used his beloved Israel to carry out His plan on Earth.
But G-d created the gentiles as His concubines; He views the gentiles as his play-things and his toys. The prohibitions against adultery in the Bible are actually meant to be spiritually interpreted as prohibitions against idolatry carried out by Israel. G-d does not care if his concubines, the gentiles, are promiscuous; in fact it is to be expected.
And so I put it to you, that gentiles are permitted to engage in acts of lust, for two main reasons: 1) idolatry is frequently equated with adultery in the Bible which proves that G-d is jealous against His people going after other gods as opposed to human beings forming passionate trysts (which instinct he made and put into his creations in the first place,) and 2) inasmuch as the gentiles have no real purpose on Earth but to interact with Israel and fulfil G-d's masterplan, and insofar as gentiles are spiritually destitute compared to Israel, it is permissible for them to find happiness in relationships with several different women, even women of ill repute, because they cannot find any lasting meaning in life on account of their not having any really significant purpose in being alive.