One week later, she and her husband returned to the doctor’s
office. The doctor took the husband aside and told him,

"Sir, I’m afraid I have some bad news. We accidentally mixed your
wife’s blood sample with another patient’s, and we have no idea
whose is whose. The bad news is one has Alzheimer’s disease, and
the other has AIDS. I want you to come back in another week and
by then I should have it all sorted out."

The man looked scared and said, "That’s terrible, doc, what
should I do until then?"

"Well, when you’re driving home today, drop her off two blocks
away from your house. If she makes it home, don’t fuck her!"