Train journey

An old woman, a young woman, and Englishman, and an
Irishman are travelling in the compartment of a train
together across the British countryside.  Each of the four
of them is ignoring the other three.
Suddenly, the train enteres a tunnel, and the compartment is
thrown into pitch blackness.  Out of the darkness comes the
sound of a kiss, then the sound of a slap.
The train leaves the tunnel, and the travellers act as
though nothing happened.
The old woman, however, is thinking to herself, "Look at
that young woman sitting there next to me, acting as if
nothing happened.  I KNOW the Englishman kissed her."
The young woman is thinking to herself, "Why would an
Irishman kiss an old lady?"
The Englishman is thinking to himself, "I didn't to
anything! Why'd I get MY face slapped?"
And the Irishman is thinking to himself, "How do you like
that?  I kiss the back of my hand, slap an Englishman in the
face and get away with it!"