Paris Hilton got on the microphone at a packed Vegas club and lavished Christina Aguilera with praise - and in the process revealed her as-yet-unconfirmed pregnancy. "Congratulations to the most beautiful pregnant woman in the world. You're gorgeous," Hilton announced at 2 a.m. Sunday morning at an Aguilera-hosted party at LAX in the Luxor. Aguilera, who has never confirmed being pregnant despite a visible bump beneath her pink chiffon minidress, appeared temporarily shocked as she sat in her perch in the elevated VIP booth. She sank her head into the shoulder of husband Jordan Bratman as her friends looked stunned. She quickly recovered, and the two looked at each other and laughed as the crowd erupted in applause. Aguilera's rep declined to comment.