Sarah Kendall, Mark Watson, Alexei Sayle and other standups recall what happened when they came face to face with their toughest critics after a showSimon Munnery: I married my hecklerMy most unsettling heckle wasn't verbal. I was struggling on stage. My material wasn't funny. My face wasn't funny. I'd forgotten the meaning of funny. I tried some banter and asked a bloke in the front row what his name was. He answere…