Jokester by Isaac Asimov - What really happened to the traveling salesman and the farmer's daughter–and why? Here's the ultimate, horrifying answer...

Noel Meyerhof consulted the list he had prepared and chose which item was to be first. As usual, he relied mainly on intuition. 

He was dwarfed by the machine he faced, though only the smallest portion of the latter was in view. That didn't matter. He spoke with the offhand confidence of one who thoroughly knew he was master.

"Johnson," he said, "came home' unexpectedly from a business trip to find his wife in the arms of his best friend. He staggered back and said, 'Max! I'm married to the lady so I have to. But why you?'"

Meyerhof thought: Okay, let that trickle down into its guts and gurgle about a bit. 

And a voice behind him said, "Hey." 

Meyerhof erased the sound of that monosyllable and put the circuit he was using into neutral. He whirled and said, "I'm working. Don't you knock?"