I'm sorry, I know you preempted this with saying you're not racist at the end, but everything you said it so very wrong and is a gross example of Orientalism. What you describe is an extremely, extremely small part of Muslim culture, and you're either naive or racist if you think people aren't dating and fucking their hearts out in every country of the world with whoever they choose. It may not be as open as in the Western world, and it may not happen as often, but it happens non-stop.

Extremists are called extremists for a reason: they're on the fringes of societies. We still have cults and religious nuts here that do very similar things, and Western, first-world countries are still the primary buyers of sex slaves.

These things are just as condemned in Nigeria as they are in America; and furthermore, Nigeria isn't some backwards third-world country. There is little doubt that they are going to be one of the wealthiest nations in the world in the next fifteen to twenty years, and already an economic powerhouse.