At a hotel in Las Vegas, a lady rushed out of the Manager's office to get a drink at the water fountain in the lobby. a few minutes later she came out for another drink. this time she was followed by a man.

There was a mirror behind the fountain. when the lady she raised her head she saw that the man behind her had a knife in his upraised fist. she screamed. the man lowered his knife and both of them started to laugh.

What is Going on?