There's this 70 year old virgin named Mary and she's sitting around the house one day when all of a sudden she notices this itch in her crotch.
So she goes to the doctor and he takes some tests and tells her to come back a week later for the results.
She comes back a weeks later and the doctor tells her she has the crabs. Mary flips out because she knows there's no way she could have the crabs, her being a virgin and all.
So she goes to another doctor and he tells her the same thing. Then she goes to a third doctor, a younger guy, and he takes some tests.
She comes back a week later for the results and he says, "Mary, I have some good news and some bad news. The good news is, you don't have the crabs. The bad news is your cherry rotted and you have fruit flies."