Sixty-year-old Bill went to the doctor and said, "Doctor, I'm worried about my wife, she doesn't look well."
"No problem," said the doctor, "I'll give her a thorough examination."
Fifteen minutes later the doctor spoke to Bill in the waiting room. "Bill, I've examined your wife and she's suffering from one of two conditions: aids or alzheimer's!"
"What the hell! Are you kidding me, doc? Aids or alzhiemer's???"
"Yes, aids or alzheimer's."
Bill was shocked. "So what can I do, doc? How can I tell which condition she has?"
"When she's finished dressing," said the doctor, "and joins us here in the waiting room, I want you to give her a shopping list and tell her that she has to make her own way home on foot, after doing the shopping."
"Doctor, we live two miles away, via a maze of convoluted lanes."
The doctor replied, "Precisely, Bill, and when you get home and find that she's already there with the shopping intact ....do NOT fuck her!"