07/19/2011 at 10:20 AM EDT
? Leonardo DiCaprio
added a new member to his posse – Bradley Cooper
– during a night out at Beacher's Madhouse inside the Hollywood Roosevelt Hotel
. The guys snuck into the club before 1 a.m. and took a seat in the front row for the vaudeville show. DiCaprio cheered for the burlesque performers and seemed more animated than usual. Grabbing Cooper's attention? The same troop of burlesque dancers.