Couple in their eighties have just finished lunch, when the old fella gets up and starts putting on his coat.
"Where are you going?" his wife enquires.
"I'm going to the doctor for some of that Viagra" he says
At that, the old lady starts to put her coat on.
"Where are you going?" he said
"To the doctor?" she replied
"What are you going to the doctor for?"
"Well" she said "If you're going to get that rusty ol' thing out again, I'm going to get a tetnus shot!"