But it makes sense for him to say "you're too tense", too, as the man walking into the bar is obviously tense and stressed.
That way around there is no pun though. The pun is that the statement is an accurate, though very out the ordinary, response to what the man is saying that also happens to be a comment on the man's mental state.
I'm sure you and Stephen have a good reason to say it's a pun one way around and not the other, but I really don't see it... perhaps the pun is such a quintessentially English kind of humour that you all have nuances and subtleties to them that escape non-native speakers. 
That might be true
*MySmiley*
Robert Graves "There is no money in poetry, but then there is no poetry in money, either."
Henning Mankell "We must defend the open society, because if we start locking our doors, if we let fear decide, the person who committed the act of terror will win"
Robert Graves "There is no money in poetry, but then there is no poetry in money, either."
Henning Mankell "We must defend the open society, because if we start locking our doors, if we let fear decide, the person who committed the act of terror will win"
A man walks into a bar
- 30/09/2012 12:55:15 PM
695 Views
Shouldn't the punchline be-
- 30/09/2012 07:04:15 PM
457 Views
How do you figure that?
- 30/09/2012 09:31:24 PM
406 Views
He's right
- 30/09/2012 10:30:01 PM
429 Views
Still don't get it.
- 30/09/2012 10:39:51 PM
467 Views
Bloody furriners!
- 30/09/2012 11:26:38 PM
435 Views
Is it?
- 01/10/2012 01:11:32 AM
542 Views
*NM*
Three bearded men walk into a bar, wearing turbans...
- 30/09/2012 10:31:29 PM
454 Views