Miley Cyrus celebrated the release of her new song “We Can’t Stop” with Justin Bieber and friends at Beacher’s Madhouse nightclub in LA. Sources tell us Bieber arrived at the lounge at about 11:30 p.m. with a full security team and pals including rapper Lil Twist and singer Quincy Brown (the son of Sean “Diddy” Combs’ on/off girlfriend Kimberly Porter). Cyrus — who claims she’s still engaged to actor Liam Hemsworth — and Bieber were spotted flirting, partying and dancing together.