- "Yes sir" - ?

If he is ex-military...which he may be...

...answer with "As you were!"...and then proceed to do yourself what you asked him to do.

He will laugh out loud.

When I grew up in the South, everyone that wasn't a m'am was a sir.

In the military, the proper response to an order is "Sir!", not "yes sir". "Yes sir", allows the possibility of the response being "No sir", and that isn't really a possibility.

Once again Frank you've made my day