I am an atheist so take my opinion for what you will. There is nothing that prevents a Christian or anyone else from living by the golden rule. The Bible may have many passages that refer to polygamy, but instead of trying to wade through scripture, just ask yourself would you want to marry or date a woman who was in sexual relationships with other men. Probably not, at least you would expect her to break it off others if you were going to be her SO. Likewise, you could offer the same to her. Nothing in the Bible would prohibit application of this simple principle.
The Bible is full of passages that are not really relevant:
"And I say to you: whoever divorces his wife, except for sexual immorality, and marries another, commits adultery.”
Matthew 19:9 ESV
But does that mean you cannot date woman who divorced her husband for abuse and cruelty?
The Old Testament is nothing to go by since no fault divorce doesn't allow stoning:
The Hebrew Bible (the Tanakh or Old Testament) prohibits adultery in the seventh of the Ten Commandments (Exodus 20:12) (sixth Commandments in Christian enumeration and in verse Exodus 20:14). Adultery in traditional Judaism applies unequally to both parties.
For instance, the Old Testament book of Leviticus prescribes capital punishment for adultery between a man and married woman, though not for adultery between a woman and a married man.
And the man that committeth adultery with another man's wife, even he that committeth adultery with his neighbour's wife, the adulterer and the adulteress shall surely be put to death. (Lev. 20:10).
Furthermore, Deuteronomic code prescribes stoning not only for female extramarital sex, but also for female premarital sex in the case where the woman lies about her virginity.
If any man take a wife, and go in unto her, … and say, / I took this woman, and when I came to her, I found her not a maid. / … But if this thing be true, and the tokens of virginity be not found for the damsel: / Then they shall bring out the damsel to the door of her father's house, and the men of her city shall stone her with stones that she die. (Deut. 22:13-21).
It also prescribes the same for engaged women who lie with another man, under the premise that if she allows the action without protesting, this indicates willingness.
If a damsel that is a virgin be betrothed unto an husband, and a man find her in the city, and lie with her; / Then ye shall bring them both out unto the gate of that city, and ye shall stone them with stones that they die; the damsel, because she cried not, being in the city. (Deut. 22:23-24).
Could you accept dating and having sex with intent of marrying is you turned out to be compatible? It would seem that not having sex might be a deal killer for many women, even Christians. They will want to test drive before living together or marrying.