Suddenly the train went through a tunnel and, as it was an old style train, there were no lights in the carriages and it went completely dark. Suddenly there was a kissing noise and the sound of a really loud slap.
When the train came out of the tunnel the woman and the Englishman were sitting as if nothing had happened and the Frenchman had his hand against his face where he had been slapped so hard he almost passed out.
The Frenchman was thinking: 'The English fella must have kissed her and she missed him and slapped me instead.'
The woman was thinking: 'The French fella must have tried to kiss me and actually kissed the Englishman and got slapped for it.'
And the Englishman was thinking: 'This is great. The next time the train goes through a tunnel I'll make another kissing noise and slap the heck outta that French bastard again.'