GRANDPA

Three mischievous grandmas were sitting on a bench outside a nursing home.

Soon a grandpa walked by, and one of the old grandmas yelled out, "We
bet we can tell exactly how old you are."

The old man said, "There ain't no way you can guess it, you old fools."

One of the ornery grandmas said, "Sure we can! Just drop your
Undershorts and we can tell your exact age."

Embarrassed just a little, he dropped his drawers. The grandmas
stared at him for a while, asked him to turn around a couple of times,
asked him to jump up and down for a little while and then they all
piped up and said, "You're 84 years old!"

How in the world did you guess?"

The grandmas snickered and laughed until they damn near pissed their
pants. Slapping their knees and grinning from ear to ear, all three
happily yelled in unison: "Because we were at your birthday party
yesterday!"