Universal’s “ Fifty Shades of Grey ” has launched with a sizzling $8.6 million at 2,830 North American locations in Thursday night showings that started at 8 p.m.The tale of romance mixed with Bdsm set several records, becoming Universal’s highest-grossing latenight show ever, eclipsing the $6.5 million set by “ Fast and Furious 6.”It’s also the second-highest grossing R-rated latenight opening behind “The Hangover 2″ at $10.4 million and the highest latenight showing for a film in February. Jamie Dornan and Dakota Johnson star in “Fifty Shades,” which expands to 3,646 theaters in North America over the Presidents Day weekend — which includes Valentine’s Day on Saturday.Universal has forecasted that “Fifty Shades,” based on E.L. James ’ massively popular novel, will wind up with a four-day launch topping $50 million over the four days. But that’s at the low end of expectations, with other analysts and rivals predicting a debut in the $70 million-$80 million range.