British actress Kate Beckinsale kicked off the new season of Ashton Kutcher's PUNK'D show in America on Monday (03APR06) - as the awkward subject of a prank played on her by ex-boyfriend Michael Sheen. Sheen contacted Kutcher and his fellow Punk'd producers and helped set up an elaborate restaurant prank, which left the Underworld actress fighting off the advances of a chubby admirer while her actor ex excused himself. Sheen then got upset with another poolside diner, who he pretended to mistake for the man who bothered Beckinsale, hurling him into the pool as the actress protested, 'Mike, it wasn't him.'" Distraught Beckinsale attempted to apologise, while Sheen fought with the original pest, throwing him into the pool as well. As he climbed out of the pool, looking to continue the fight, a mock waitress ran up to Beckinsale screaming, 'You've been Punk'd,' which left the relieved actress embarrassed and giggling. Kutcher hailed the prank a big success, but was amazed that Sheen wanted to play a prank on his ex, quipping, "BRUCE (WILLIS) would never do this to DEMI (MOORE)."