I was working as a cashier at a grocery store over a year ago. No one was in my line, so I was standing idly. I was looking toward the front doors, and usually there was someone standing there to greet customers, also to act as AP, but not at this moment.

I saw this guy with a cart with several cases of beer heading toward the front doors. He wasn't coming from any register, and he wasn't looking at anything but the doors. Just as he was about to leave, he looks around and notices me just staring at him. Then he steers the cart in front of the water bottle display we had at the front doors, and then starts pretending to look around. He fidgets for a second and then pulls out his wallet, checks inside, closes it up, puts it back in his pocket, then just leaves without the cart.