when a drunk comes in, staggers up to them, and points at Seamus, shouting, “Your mum’s the best shag in town!”

Everyone expects a fight, but Seamus ignores him, so the drunk wanders off and stick his nose into a pint of Guinness at the far end of the bar.

Ten minutes later, the drunk comes back, points at Seamus again, and says, “I just screwed your mum, and it was grand!”

Again Seamus refuses to take the bait, and the drunk goes back to the far end of the bar. Ten minutes later, he comes back and announces, “Your mum said it was the best thing since sliced bread!”

 Finally, Seamus interrupts. “Go home, Dad… you’re drunk!”