Or get a big glass of soda and place it on the edge of the table. Then accidentally spill it.
As a CCP holder, I think I would be tempted to place my 9mm tool on the table while I ate the main meal, ordered dessert and ate that, then have a couple of cups of coffee before getting up to pay the bill. And not put the 9mm away until going to pay the bill. Oh! And leave a twenty percent tip, in cash, on the table in the open for them to stare at.