LONDON—The Kim Kardashian of Islamic call girls is blazing a trail for British Muslims who are embracing a traditional form of marriage to absolve themselves of the sin of premarital sex.

By entering into a nikah mut’ah, a temporary marriage for as little as an hour, sex between two lovers suddenly becomes legit in the eyes of Allah, at least according to some generous Shia interpretations. Plenty of other scholars argue that the practice, which was laid out in the Quran, had already been rejected during Muhammad’s lifetime.

To Kamillah, a London escort with 80,000 Twitter followers, nikah mut’ah is merely an optional extra available for less than $100. On an extraordinary online photo page, she puts Kim Kardashian’s butt to shame in a “break the Internet” replica shot. Her backside and just a hint of her left breast are obscured only by baby oil, while her head is modestly covered by a traditional veil.

Indeed, the $450-an-hour escort wears a veil or hijab in most of the photographs on her booking site, even when a nipple is squarely in the center of the frame. Thus, civilizations collide in 21st-century London.

Among the reviews on the Trip Advisor-style site, a satisfied customer concludes: “Allahu Akbar! Had the best mutah experience everr.”

Another recent client was an undercover reporter for The Sun newspaper. Using the name “Fairuza,” Kamillah told him that her quickie marriage, quickie divorce service was in great demand. “It’s very popular,” she explained.

The biggest concern for Kamillah, who says she is half-Iraqi, half-Iranian, was apparently the fear that Romanian and Eastern European call girls were muscling in on her turf by pretending to be Middle Eastern and offering the same ceremony.

While there is a debate among Shia clerics about the permissibility of mut’ah, it is completely outlawed for Sunnis. Kamillah told The Sun: “I did it with one Saudi who converted to Shia Islam only so he could do mut’ah. He did it just for that reason.

“He was in London for two months. I was his wife for the two months. I lived with him and I wasn’t allowed to be with any other man. He paid very good money. He is coming back next year and we’ll do it again. It’s common for Arabs to do it.”

Nikah mut’ah is used in varying degrees of openness all over the Shia world. Iranian officials suggested last year that it should be used more frequently by Westernized couples who wanted to avoid committing adultery—a crime punishable by death.

In Britain, young Muslims are coming to similar conclusions, not just for sex but if they want to experience a Western boyfriend-girlfriend relationship, which is otherwise haram, or sinful. Omar Farooq Khan, former president of the Islamic Society at Bradford University, told the BBC Asian Network that the practice had become common on campus and was seen by many as halal, or permissible. “Definitely nikah mut’ah is on the rise now…Students are educated people so obviously they look around for a solution to their problems from an Islamic perspective,” he said.

“What else are they going to do?” he added. “They can’t just have a cold shower because it doesn’t work and otherwise they just end up doing the haram thing and having a girlfriend or boyfriend. Many people won’t talk about it, though, because it is still a taboo subject.”

Ali Selman, a green-eyed Lebanese Shia from Brooklyn, told The Daily Beast that a section of the Quran called “Al Nissa” provided the perfect get-out clause for the young man about town. “Marriage is halal, dating is haram,” he said, although he may have been stretching Allah’s tolerance with his estimated 25 temporary marriages.

If Selman was benefiting from the growth of mut’ah in the West, the rather forlorn-looking MutahMatch.com appears to have been a less successful venture. Men from London; Dearborn, Michigan; and New York are among those to post their email addresses online in the hope of hearing from adventurous Muslim women. There’s no sign of any female replies.