It may be hard to believe, but the Backstreet Boys — who released their latest album, In a World Like This, today — are celebrating 20 years as a group. We caught up with the band just before they were granted a star on the Hollywood Walk of Fame in April. A.J. McLean, Brian Littrell, and Kevin Richardson chatted with POPSUGAR at a special event they threw for fans in Hollywood as they prepped for the milestone ceremony. The guys sang a cappella for us and shared some details on their upcoming documentary, which follows them over their two decades as a group — questionable hairstyles and all! On Lindsay: Clover Canyon dress.