Wife had delivered twins

The young wife went into labor while her husband was overseas serving in the war.
The next day he got the news that his wife had delivered twins.
He got to a phone and called her right away.
“Oh honey, I’m so happy,” he said
“Who took you to the hospital?”
“Your brother, Joe, drove me, and since I had to be anesthetized he named the twins.”
The husband was horrified
“But, but, Joe is an idiot! Oh no! What did he name them?”
The wife answered, “We have a girl and a boy
Joe named the girl De-niece.”
The husband interrupted, “Well, that’s not so bad
What did he name the boy?”
“Joe named the boy De-nephew.”