06/13/2011 AT 05:00 PM EDT
celebrated model Cora Skinner
's birthday at new L.A. club The Beverly
. They sat at an outside table filled with Skinner's friends and seemed to be having a low-key celebration. At one point, though, Ross jumped on the microphone to wish Skinner a happy birthday, calling her "baby." Paris Hilton
arrived later, joining the party with her friends.