Avril Lavigne hosted a New Year’s Eve party at Prive in Las Vegas on Monday night, where the singer shocked onlookers with behavior making her look more like Paris Hilton. “It was an Avril I’ve never seen before,” a partier confessed to FoxNews.com’s Pop Tarts. “She totally let loose and was gyrating on all the couches and jumping from table to table while putting on quite the public display with her husband, Deryck [Whibley].” Check out footage of Avril and her Sum 41 hubby heading up the escalator to the party below.