December 3, 2009 1:24 pm Cheating Is Bad, Tiger Lori Wilson wonders why infidelity is so huge among celebrities right now — even Tiger Woods allegedly cheated on his wife. Dr. Stephen Treat has the answers and knows how to prevent cheating. US & World Videos 0:35 Fans of ‘The Office' got to see some of the stars at Fan Expo Philadelphia on Saturday 2:32 Rainy, chilly weather didn't stop many from enjoying festivals throughout Philadelphia 0:29 Driver found safe after carjacking in Delaware 2:23 Teen killed in quadruple shooting in North Philadelphia on Saturday evening 0:39 Teen shot near church in West Philly, two in custody