Sex sells. So this year’s Mardi Gras flaunted itself. Its cod-piece was the python-esque parade snaking up Oxford Street, a ribald, risque body of bodies-politic. Marchers fed off a frenzied live street audience of more than 100,000 with even more watching on TV. It’s a show with a capital S, buoying pink-dollar tourism and state coffers by $30 million.