A Father and his son go to the pub for a manly chat.
Son: "Dad I really would like to marry Sally from the supermarket. She's lovely in gingham."
Dad: "Well son. When I was your age I had a bike. I got around a bit in this village. You can't marry her. She's your half sister."
Son: "Errr. Ok. Then what about Mary Wilks from 'tut' tavern on 'tut' corner (this is the dialect of Bradford people). She plays the pink clarinet, thou knows?"
Father: (choking on his beer and chaser with cigarette) "No, Son, I forbid it. Her Mother and I had weekly visits to the clinic. We could have populated the whole of a South East Asia if so much hay, hadn't got intit!"
Son: "Well, that narrows it down. What about? Shagbag Sharon with the green teeth and big bloomers?"
Father: "Out of the question, boy. Her Ma never shaved but I liked the continental look. After all, she had nipples like helicopter ports."
The two vacate the bar and the son walks home sobbing. Distraught, he falls through his front door and into the arms of his waiting Mother. The father stumbles upstairs to bed.
Mother: "What ever is the matter, boy?"
Son: "Daddy, says I can't marry Sally from the Supermarket. Mary from the tavern, or Shagbag Sharon."
Mother: "You marry who you like, son. He doesn't know who your real Father is, anyway!"