A friend of mine recently told me the following story: When he was little, for a while, he had to get to school on a city bus, and his mother or father would accompany him. One morning, his mother had to go to the bathroom, so she parked him at the bus stop and told him, in case the bus came before she got back, to ask the driver to wait. It did, and he did, but the driver refused to wait. When he told his mother that, she said "That bastard!". He had never heard the word, and supposed it meant bus driver. So when, later on, his father gave him the same instruction so he could duck into the liquor store & buy a pack of cigarettes, he replied "The bastard won't do that". After a double take, his father told him not to bring home language that he had picked up in the schoolyard. He told his father he hadn't learned it in the schoolyard, but from Mommy. His father afterward had words with his mother, and from then on, "bus driver" was a code word between the boy & his mother. When they wished to disparage someone in polite company, they would say "That bus driver".