Indian bar game

A Norwegian took a trip to Fargo, North Dakota. While in a bar, an Indian on the next stool spoke to the Norwegian in a friendly manner.
"Look," he said, "let's have a little game. I'll ask you a riddle. If you can answer it, I'll buy you a drink. If you can't then you buy me one. OK?"
"Ja, dat sounds purty good," said the Norwegian.
The Indian said, "My father and mother had one child. It wasn't my brother. It wasn't my sister. Who was it?"
The Norwegian scratched his head and finally said, "I give up. Who vas it?"
"It was ME," chortled the Indian.
So the Norwegian paid for the drinks.
Back in Sioux Falls the Norwegian went into the bar and spotted one of his cronies.
"Sven," he said, "I got a game. If you can answer a question, I'll buy you a drink. If you can't, you have to buy me vun. Fair enough?"
"Fair enough," said Sven.
"Ok," the Norwegian said, "my father and mudder had vun child. It vasn't my brudder. It vasn't my sister. Who vas it?"
"Search me," said Sven. "I give up, who vas it?"
The Norwegian burst out, "It vas some Indian up in Fargo, North Dakota!"