Three old ornery grandmas were sitting on a bench outside a nursing home when an old man walked by, and one of the grandmas said, "We bet we can tell how old you are." The old man said "There ain't no way you can guess it" One of the ornery grandmas said: "Sure we can! Drop your pants!" He did. The old grandmas stared at him for a while and then they all piped up and said, 'You're 84 years old!" The old man was stunned. "Amazing. How did you guess?" The ornery old grandmas, laughed and slapping their knees, said, "You told us yesterday".