Leonardo DiCaprio and his on-again, off-again love, model Bar Refaeli, are acting single. On September 13, Bar, 23, partied in Las Vegas at the grand opening of LAVO. “She kept saying she needed to meet a hot guy,” an insider says. “She was on the prowl.” Maybe that’s because the night before, Leo, 33, was at Butter restaurant owner Richie Akiva’s birthday party at NYC’s 1Oak without her. “He kept calling it a great boys’ night,” an onlooker says. “He was taking shots of Grey Goose and talking to everyone.” The pair, who began dating in early 2006, haven’t been spotted together since July 14 in LA. “Leo’s been a fixture on the nightlife scene recently,” an insider tells In Touch. “Bar was having a blast,” an onlooker tells In Touch about her night in Las Vegas.