07/28/2010 03:36 pm ET Updated Dec 06, 2017

Christina Applegate Pulls Pregnancy Prank On Kimmel (VIDEO)

Christina Applegate recently told the world she and husband Martyn LeNoble are expecting their first child, but when she appeared on "Jimmy Kimmel Live" last night she looked like she was about to give birth right on the set. In what she jokingly dubbed a "Spencer/Heidi publicity stunt kind of thing," Applegate walked on set with a sweatshirt shoved under her dress to appear to be more pregnant than she is. She removes the fake baby bump to reveal her actual, much smaller one before telling Kimmel about the perils of pregnancy including "psychosis." Judging by her hilarious behavior at the top of the show, we'd agree she's going a little cuckoo.