Let me preface this with a disclaimer. I don't entirely know your perspective or what you are really trying to figure out on this matter.
Let the husband render to his wife the affection due her, and likewise also the wife to her husband. The wife does not have authority over her own body, but the husband does. And likewise the husband does not have authority over his own body, but the wife does.
What is the polygyny perspective on this text in 1 Cor 7?
The polygyny perspective on this is exactly the same as the monogamy perspective. Nothing changes. The wife is due sex from her husband and can expect it. The husband is due sex from any of his wives and can expect it. That's all the passage is about.
You must first understand the context and not assume anything outside of the context. And that context is specifically given. Paul said they wrote him a letter and had a question. He's answering that question, so what he writes about is specific to the question and not a general treatise on the authority structure between a husband and wife. It's specific to sexual duties and expression in marriage.
1Co 7:1
Now concerning the things whereof ye wrote unto me:
It is good for a man not to touch a woman.
They had a question about sexual contact between men and women. The context reveals that in the following verses because the topic is sexuality and the avoidance of fornication (sexual immorality).
1Co 7:2
Nevertheless,
to avoid fornication, let every man have his own wife, and let every woman have her own husband.
To avoid fornication you should be married.
1Co 7:3
Let the husband render unto the wife due benevolence: and likewise also the wife unto the husband.
In marriage you're allowed to engage in sexual expression and it not be fornication. Not only that but both the husband and wife have a duty to render what is
due. And what is due is sexual in nature, this is clear by the context. The Greek word is actually
(kindness/enthusiasm/good will). Really means a lot when you think about it. We are to serve the Lord with εὔνοια Ephesians 6:7. How should we serve God? With cheerfulness, wholeheartedly, enthusiastically, with good will, with our all, joyfully. Not begrudgingly, or with half hearted effort, grumbling, lukewarm, apathetic, listless, dispassionate, lackluster. So how should a husband serve his wife in the bedroom? How should a wife respond when he wants her?
1Co 7:4
The wife hath not power of her own body, but the husband: and likewise also the husband hath not power of his own body, but the wife.
According to the context we're talking about sex, not anything else. The wife does not have the authority to reject her husband's sexual needs/desires, he has the power to compel her to perform what he is
due. And He does not have the authority to reject her sexual needs/desires, she has the power to compel him to perform what she is
due.
Paul does not diverge from the previous context and wildly start taking about authority structure in reference to finances, or hierarchy of authority before God. The wife does not own her husband's body. The wife is due sex and she has a right to demand what she is owed. That is the extent and the totality of what this passage is discussing.
1Co 7:5
Defraud ye not one the other, except
it be with consent for a time, that ye may give yourselves to fasting and prayer; and come together again, that Satan tempt you not for your incontinency.
If you defraud, you are said to have not given what is due. This is perfectly in alignment with the entirety of the passage. The husband is owed sexual expression with his wife, and she is owed the same with her husband. To hold back from that is to defraud the other. We should not defraud our spouse. We can withhold what is due
with consent for a time so we can give ourselves to fasting and prayer. If a spouse defrauds the other in this matter we are told that Satan will tempt the one being defrauded.
Now that we've exegeted the passage, does this power or authority change anything if the husband has more than one wife? Nope. If a man has 5 wives, they can all demand he get in the bed and take care of them all. I don't see how it's a hard and fast rule that the dude must drop anything the moment she says she wants it. But the understanding is that she is due sexual fulfillment in general.
