This one's a howler.

Two golfers just came back to the club house for a drink. They overheard two Irish men talking,"I used to live in Dublin too," said one. "I moved here when I was 10 too," said the other. "My last name is O'Leary too." The two golfers that had heard asked a man walking by, "Who are these guys?" The man said, "Oh! That's the O'Leary twins, there just drunk."