the old twins and the fork in the road riddle

[rod91]

Paradoxes are more fun than riddles

 

But here's one for ya:

 

A man walks into a pub and sits down at the bar, and simply orders a water. The bartender looks at the man, and then, quickly pulls out a shotgun and points it at the man. The man says "Thank you," and leaves. Why did they behave this way?

 

Hah