After a grueling 45 days at the tony Promises rehabilitation facility in Malibu, little Lindsay Lohan felt she had to reboot her social life on the “outside,” and headed (straight) to the glittering armpit of celebrity decadence, Las Vegas, and hung with 10 or so friends at the nightclub Pure, ground zero for tabloid-quality partying, where her assistant was the focus of a surprise birthday party. Not surprising is that Lohan drank only water; for a while, she’ll be wearing a cumbersome but fetching alcohol-monitoring ankle bracelet like the one Tracy Morgan wears, so that “there’s no question of her sobriety when she goes to places where alcohol is served,” said Lohan’s suddenly back-fielding-questions publicist Leslie Sloane, who is sure to be currently embroiled in thi new business of those naked photos of Lohan taken by Calum Best that were just hacked off her computer. (TMZ; photo: Chris Weeks/Wire Image)