Polygamy in ZAMBIA

I met a man in a prenatal clinic at our rural health center. He brought two wives at the same time!
In ZAMBIA, they have a culture of polygamy. In urban areas, it's getting to be an outdated culture, but in rural areas, it's still around.

I asked that man if he planned this or it was just a coincidence. He replied that it just occurred accidentally. So I couldn't say "congratulations!" to them. I just said that I hope they will have healthy babies and be happy. One of his wives replied, "We are happy because when I am tired, she helps me." She thought that I think it's pathetic.

Although she said that, I can't believe African women accept polygamy. I spent about a year in NIGER before ZAMBIA. Most of Nigerians are Muslims and Allah allows them four wives. But it is likely that they argue. Sometimes wife versus wife, sometimes wife versus husband. I think jealousy is a universal feeling all over the world. What if my husband brought another wife, I would be mad. I asked my female colleagues if they would accept other wives with their husbands ? Their ansers were "No".

Even if a man has only one wife, having more than one sex partner at same time is popular here. I want to know what women think about it. Do they admit it as a part of their culture?