Non illegitimi carborundum (don’t let the bastards wear you down).
Groping for an imaginary gun might get them to reconsider, if nothing else worked. Even better if it’s not imaginary.
I had to put my hand on my revolver once. I didn’t have to pull it but the act did not go unnoticed by the the three thugs that were preparing to rob me as I pumped gas into my truck. One looked at another and shook his head and they all slunk back into the shadows, including the one standing in the middle of the road acting as a lookout. This was wise on their part as the plan I was preparing to execute involved gasoline and muzzle flash.