There’s a very specific reason why Beyonce chose to do this campaign in a laundromat, and there’s no way that people under the age of 50 know about it. In 1985, a Levi’s ad for its 501 jeans made history: Nick Kamen’s sensual and unexpected striptease in a laundromat left no one indifferent. Even Madonna fell under his spell, and he aroused an irresistible desire among boys and girls alike to frequent laundromats. Even today, you only have to hear the opening bars of Marvin Gaye’s song I Heard It Through the Grapevine to remember that iconic advertisement. But what’s even more extraordinary is that the spot boosted UK sales to such an extent that Levi’s had to stop airing it, unable to keep up with consumer demand. And now the jeans brand is hoping to repeat the feat with Beyonce…