If I put my hand up your skirt I will be able to tell your exact age.”
There was no one around, so the woman said, “What the hell?” and let him slip his hand up her skirt.
After feeling around for a while, the old man said, “OK, You are 47.”
Stunned, the woman said, “That was brilliant! How did you do that?”
The old man replied, “I was behind you in line at McDonald’s.”