a man with a dog

A man walking down the street one morning sees two hearses, one behind the other moving slowly down the road.
Walking behind the hearses is a man with a big dog.
Walking behind the man is a single line of men stretching right down the road.
Curious, he wanders over to the man.
“Sorry for you loss, but you’ll have to excuse me this is a very strange sight.”
The man with the dog explains
“In the first hearse is my wife, sadly my dog attacked her and killed her. In the second hearse is my mother in law, who went to assist her daughter and was also sadly killed.
After a short pause the first man asks.”Can I borrow your dog?”
The second man nodding backward say “Yes sure join the queue”