Mathew 19:9 blows your perverted theory out of the water in the strictest sense. God does have sexual standards He laid out very clearly; if you don't repent from them you are dead a Spiritual sense. You obscure allowing based on free will for approval.
In the end Solomon learned his lesson stating, "I amassed silver and gold for myself, and the treasure of kings and provinces. I acquired . . . a harem as well–the delights of the heart of man...Everything was meaningless, a chasing after the wind; nothing was gained under the sun"Ecclesiastes 2
Um, Matthew 19:9 doesn’t say that:
And I say unto you, Whosoever shall put away his wife, except it be for fornication, and shall marry another, committeth adultery: and whoso marrieth her which is put away doth commit adultery.
It actually says you CAN fornicate with another, you just can’t marry a woman whilst married to someone else. Mind, I recall there are passages that discommend fornication in the first place, but Matthew 19:9 isn’t one of them. Matthew 19:9 seems to permit concubines.