nypost.com -- The man was waiting to board American Airlines Flight 1140 to Dallas when a cheerful gate agent began welcoming everyone with the Yuletide greeting while checking boarding passes. The grumpy passenger, who appeared to be traveling alone, barked at the woman, “You shouldn’t say that because not everyone celebrates Christmas.” The agent replied, “Well, what should I say then?” “Don’t say, ‘Merry Christmas!’ ” the man shouted before brushing past her. Once on the plane, he was warmly greeted by a flight attendant who also wished him a “merry Christmas.” That was the last straw. “Don’t say, ‘Merry Christmas!’ ” the man raged before lecturing the attendants and the pilot about their faux pas. The crew tried to calm the unidentified man, but he refused to back down and continued hectoring them. He was escorted off the plane as other fliers burst into cheers and applause.