Viagra for Gramps

This old man in his eighties got up and was putting on his coat.
His wife said, "Where are you going ?"
He said, "I'm going to the doctor."
And she said, "Why? Are you sick?"
"No," he said. "I'm going to get me some of those new Viagra pills."
So his wife got up out of her rocker and was putting on her sweater and he said, "Where are you going?"
She said, "I'm going to the doctor too."
He said, "Why?"
She said, "If you're going to start using that rusty old thing again, I'm going to get a tetanus shot."