Big mouth Paris Hilton blew Christina Aguilera‘s preggers cover last night at the Las Vegas LAX nightclub opening, according to TMZ. According to a video posted on the TMZ site, Paris grabbed a mike and called her "the most beautiful pregnant woman in the world!" — surprising the parents, who hadn’t made an official announcement.

Ouch. Bet Nicole Richie‘s thinking, "Oh, really? Most beautiful? And what am I, chopped liver?"

Photo credit: WireImage

Posted by:Elizabeth Snead