Three leaders of the big beer companies meet for a drink. The president of Budweiser orders a Bud, Miller's president orders a Miller and the president of Coors orders a Coors. When it is Guinness' turn to order he orders a soda.
"Why didn't you order a Guinness?" everyone asks.
"Nah," Guinness replies, "If you guys aren't having a beer neither will I."