Tom and his friend Bob, and a beautiful girl and an old woman are sitting in a train. The train goes through a tunnel. It gets completely dark.
Suddenly there is a kissing sound and then a slap! The train comes out of the tunnel. The woman and Tom are sitting there looking perplexed.
Bob is bent over holding his face which is red from an apparent slap.
The old woman is thinking: “Bob must have tried to kiss that girl and has got slapped."
Bob is thinking: “Damn it, Tom must have tried to kiss the girl, she thought it was me and slapped me.’’
The girl is thinking: “Bob must have moved to kiss me, and kissed Tom instead and got slapped.”
Tom is thinking: “If this train goes through another tunnel, I could make another kissing sound and slap Bob again."