Rabbi Moishe, Mullah Nasruddin and a Nun were sitting together in a carriage in a train going through Jerusalem.
Suddenly the train went through a tunnel. As it was an old style train, there were no lights in the carriages and it went completely dark. Then there was this kissing noise and the sound of a really loud slap.
When the train came out of the tunnel, the Nun and Rabbi Moishe were sitting as if nothing had happened, and Mullah Nasruddin had his hand against his face as if he had been slapped there.
Mullah Nasruddin was thinking: 'Rabbi Moishe, must have kissed the Nun and she missed him and slapped me instead.'
The Nun was thinking: 'Mullah Nasruddin must have tried to kiss me and actually kissed Rabbi Moishe and got a slap for it.
Rabbi Moishe was thinking: 'This is great. The next time the train goes through a tunnel I'll make that kissing noise and slap Mullah Nasruddin again.