A friend of mine once said something similar to a girl in line at a movie theater. The girl had tried to cut in front of us, and my friend pointed out that the line started in the back of the room. The girl got angry and snapped to my friend, "Well, you’re fat."
My friend pulled a face of absolute shock and horror, and began patting herself frantically. “My God,” she gasped. “You’re right!”
The girl retreated to the back of the line with a look of blank incomprehension while everyone around us who had heard the exchange laughed.