@tycho, my presentation is definite. Can you point out where you have doubt?

Yes, the agreement is universal truth because the truth is one from one source, the Creator of this universe. Same God who sent Noah, Abraham, who sent David, who sent Musa, who sent Jesus and who sent Muhammad peace be upon them all... You see God sent to each nation a Prophet as a warner, and some of them with a Scripture as a guidance for that particular nation, and the scripture had same message, but different languages.

long time ago people used to call it eating mangoes
get it... eating juicy mangoes

And why isn't @masukuma posting a selfie of him eating something?

Why would you want to blind fold your wife? Modesty is a distinctive part in our religion.

It was narrated from Ibn ‘Abbas that the Messenger of Allah (ﷺ) said: “Every religion has its distinct characteristic, and the distinct characteristic of Islam is modesty.’”(Ibn Majah)

Anyway, it is haram based on below reports from the Sunnah of Prophet Muhammad s.a.w

0. Openly
It was narrated by 'Abdur-Rahman bin Abi Sa'eed [Al-Khudri]: "The Messenger of Allaah ﷺ said: 'A man is not to look at the 'Awrah of a man, and a woman is not to look at the 'Awrah of a woman. A man is not to be alone with a man under one garment, and a woman is not to be alone with a woman under one garment.'"[Jami` at-Tirmidhi Book 43, Hadith 3023 (Grade: Saheeh)]

1. 'blind folding'
Shyness is part of iman in Islam.
Anas narrated that the Messenger of Allah pbuh said:
"Al-Fuhsh (Obscenity) is not present in anything but it mars it, and Al-Haya' (modesty, bashfulness) is not present in anything but it beautifies it." [Jami` at-Tirmidhi Book 27, Hadith 80 (Grade: Saheeh)]

Prophet Muhammad pbuh did not blind fold his wives. He kept them in a separate houses visiting them on an alternate basis, showing that group sex is not allowed in Islam
It was narrated that Aishah (RA) said: "The Messenger of Allah used to divide his time equally among his wives, then he would say 'O Allah, this is what I am doing with regard to that which is within my control, so do not hold me accountable for that which is under Your control and is beyond my control.'" (Ibn Majah,Sahih)

2. The same thing given to other prophets & messenger:
Say: "We believe in Allah, and in what has been revealed to us and what was revealed to Abraham, Isma'il, Isaac, Jacob, and the Tribes, and in (the Books) given to Moses, Jesus, and the prophets, from their Lord: We make no distinction between one and another among them, and to Allah do we bow our will (in Islam)." (Surah Al-Imran, 3:84)

Every nation was sent a messenger:
"And for every nation is a messenger. So when their Messenger comes, it will be judged between them in justice, and they will not be wronged." [Quran 10:47]

Some of these Messengers are mentioned in the Quran and some of them are not: "And We have certainly sent messengers before you [O Muhammad sallallaahu `alayhi wa sallam (may Allah exalt his mention)]. Among them are those [whose stories] We have related to you, and among them are those [whose stories] We have not related to you.... So when the command of Allah comes, it will be concluded [i.e., judged] in truth, and the falsifiers will thereupon lose [all]." [Quran 40:78]

3. ALL cultures exhibit the same response other than man-made who went astray... learn from what happened to them:
"… So proceed [i.e., travel] throughout the earth and observe how was the end of those who denied." [Quran 3:137]

OMG!

From this it doesn't necessarily follow... It's a possibility- what you've deduced.

You're trying an impossibility.

These are general postulates. But they involve a lot of improvisation in between. Like how you've improvised on the issue of blind folding.

But even more important is the fact that, that's how humans will tend to reason, especially in a discretely changing environment.

There are no necessary morals, yet morals will tend to impose themselves as necessities.

Another thing that is important is that, there exists at least one understanding of God that would allow so much diversity as to preclude the idea of 'necessary moral codes'. So to say that God spoke to X and Y and therefore X is Y is markedly false.

Religion is good, but mostly when we know it's limits and use it accordingly.

True, group also means family... it also means living close together... but no group sex in Islam. But you can visit your wives on an alternate basis, one after another. The authority is from the below hadith:

It was narrated that Aishah (RA) said: "The Messenger of Allah used to divide his time equally among his wives, then he would say 'O Allah, this is what I am doing with regard to that which is within my control, so do not hold me accountable for that which is under Your control and is beyond my control.'" (Ibn Majah,Sahih)

First, marrying more than one is not a must. Quran 4:3 says: "...marry those that please you of women, two or three or four. But if you fear that you will not be just, then [marry only]"

Secondly, there are many reasons why man is allowed to marry more than one wife. You see, not all men are the same... (1). there are men EVEN ONE is no, no! (2). there are men one is okay ad enough, (3). there are those one wife is not enough. This is the category we are talking about. Remember there are some women who don't mind sharing. We're not saying all women want to share. We are saying some don't mind. And these category agree to share the man who needs more than one.

Thirdly, why not mpango wa kando? Answer lies in your word "wife"... Why wife in the first place? So the reason why woman wants to be wife is the reason why not mpango... It is about the institution of marriage, approved by God Almighty. Extramarital affairs is haram in Islam. The woman in this relationship is disgraced and unprotected. A woman in marriage is honoured.