Ryan Cabrera Wild Rock Star?

9/8/2007 10:59 AM PDT

Ryan Cabrera -- Wild Rock Star?

No, that's not Hessian rocker/Mischa Barton-ex/Whitestarr frontman Cisco Adler. It's Ryan Cabrera -- former Ashlee Simpson BF and squeaky clean pop singer.

Cabrera was doing his best rebellious rock star impression while hanging out at the Star Lounge at the Hard Rock Hotel and Casino in Las Vegas. Party on, wild man!