The show must go on! Despite being “very angry” with Mary Cosbyover allegedly hurling the “R-word” slur about Lisa Barlow’s son, sources with knowledge about the situation toldRadarOnline.com that the pair have already moved on. “The ladies are all good,” our insider shared, pointing out that Cosby and Barlow are filming in Mexico for a cast trip. While Barlow might be able to overlook the recent events for the sake of filming, sources said she likely won’t forget it. As RadarOnline.com reported, Cosby allegedly called Henry, who’s 12, the R-word during a fiery exchange while filming forThe Re…