This is an old puzzle and won't take long to be solved, but I think it's a useful addition to the site.
In a hotel in France at the time of the German occupation, two men and two women are in a lift moving downwards. One of the men is a uniformed German officer, the other a secret member of the French resistance. One of the women is young and beautiful, and the other is an elderly lady.
A momentary power cut causes the lights to go out for thirty seconds, leaving the four people in pitch blackness. There is the sound of a kiss followed by a punch. The lights come back on again, revealing that the German has just acquired a black eye.
The old lady thinks, "It's nice to see that young women these days can look after themselves. That rude German must have kissed her, but she gave him what for!"
The German thinks, "Ow! That schweinhund Frenchman must have kissed this young lady, and she punched me by mistake."
The young lady thinks, "What odd people these Nazis are! He must have ignored me and kissed this old woman, or even the other man, and got punched for his trouble."