WASHINGTON, February 16: Former White House intern Monica Lewinsky claimed she hid in the President's office to perform oral sex on him after he finished meeting with Mexican leader Ernesto Zedillo, Newsweek says.Lewinsky told a friend, Linda Tripp, she was stashed in President Bill Clinton's study off the Oval Office last November during a meeting between the two leaders, according to an ``informed source.'' Newsweek said Tripp secretly tape recorded conversation with Lewinsky that became part of the investigation in the sex-and-perjury scandal.