I read recently where that is one of the prime reasons there is so much inbreeding in many muslim countries, because the remotest male a female can spend time with sans chaperone is a first cousin, ergo, much more sexual activity in that arena.
They view any woman hanging around with anyone further out than that as a loose woman.
Any unmarried woman turning up pregnant would find hell on earth. As we have seen here in the U.S., Canada and Europe, they are quite enthusiastic about their "Honor Killings."
Wealthy and powerful men marry as they can afford. Poor men take what they can get. They tend to marry first cousins. Often, two closely related men will agree to "trade" sisters or daughters to marry.
Contrary to what the liberals tell you, it is not a "beautiful and sophisticated" culture.