"You mean I can have four wives WITHOUT becoming a Muslim? Wow! - is there an application form available on line? But I wonder why Polyanna is famous for always being so cheerful."
Convert to Judaism or the Church of Latter Day Saints.
Judaic law says a man can have as many wives as he can each service 4 times per week. Makes for a busy beaver, eh? Obviously, over time, Jewish women weren't accepting the ploy, and things are as they are for the most part. For those not familiar with Jewish laws regarding how to live, you can find searchable Talmuds (the codified Jewish laws, accomplished by Maimonides, author of that famous quote "Give a man a fish and you feed him for a day; teach a man to fish and you feed him for a lifetime"), a codified compilation of all the books of Jewish laws of his day.
There's a Rabbinical tale of Solomon, who purportedly had 1,000 wives and concubines (a political necessity of the day for monarchs), when rebuilding the temple, later known as the second temple (the Babylonians destroyed the first leading to the first Jewish diaspora) the priests of the Temple tried to depose Solomon, claiming there was no way Solomon could satisfy each of those women 4 times a week (a concubine held similar status to a wife for such obligations). Solomon the Wise, resolved the problem by putting all the opposition priests to death, and appointing new ones who favored him. A terrific solution to impeachment threats, every sitting president should find his or her tenure so easy.
Barely able to keep up with one wife myself (and sex is a small part of that issue), I can't understand why you or any other man would want more than one. Some days I wonder about having one?
So, if you don't mind a little nip and tuck, convert to Judaism and get all the wives you want. But if want a less painful experience, Mormonism is the way to go. The Book of Mormon implies that circumcision is the way to go, but Mormons seem to ignore that little sacrifice other than the usual parental search for cleanliness for their children. An adaption from those original scriptures of the Torah. Most Mormons have let that practice fall by the wayside, like most Christians. (These last two sentences are purposefully ambiguous.)