The train goes into a tunnel and a few seconds later there's the sound of a loud slap. When the train emerges from the tunnel, the Australian has a red handprint on his cheek.
NO ONE SPEAKS.
The old lady thinks: The Australian must have groped the blonde in the dark, and she slapped his cheek.
The blonde thinks: The Australian must have tried to grope me in the dark,but missed and fondled the old lady. She slapped his cheek.
The Australian thinks: The South African must have groped the blonde in the dark. She tried to slap him but missed and got me instead.
The South African thinks: I can't wait for another tunnel, so I can smack that Aussie again!