Ed walkjes into a bar and orders a Dewers Scotch "on the rocks" (ice).
The bartender pours Ed a "well brand" that is Clunys, a scotch that Ed knowns very well.(Since he buys it for home consumption).

"Bartender, I ordered Dewers, and this is Clunys scotch!", he bellowed.

"I'm sorry sir, I must have made a mistake" sayes the bartender. "Would you like another drink"?

"Yes, And make sure it's "Dewers Scotch" this time".

Beliving that the bartender is smarter than the customer, the bartender pours Ed a "Chivas Regal Scotch", on the rocks, as requested.

"Bartender", Ed bitches, "I ordered Dewers and you have substituted 2 other scotches,this time, Chivas Regas and I am pissed! Don't you know your booze?"

The bartender, being offended, took umbridge at Ed's sarcastic comments.

"Hell Yes, I know my booze" the bartender stammered.

So, Old Ed pulled a hip flask from his pocket and offered it to the bartender.

"Jesus Christ, this taste like piss!" said the bartender.

"Your right" said Ed, in his own smug way. "But Whose is it?"