Diplomaticway
A man enters a restaurant, takes a seat, and, instead of using the napkin, takes the table cloth from the table and tucks it around his neck.
The head waiter sees it and tells the waiter to go and tell him, in a diplomatic way, that what he did was incorrect.
The waiter goes to the man and says, "Good day to you Sir.. Would you like a shave or a haircut?".