The middle-aged man went to see his doctor.
He said, "I have not been interested in sex with my wife for months, and it's peeving her a bit. Could you prescribe some Viagra so I can make love with her again?"
The doctor replied, "Viagra doesn't work for everyone and it's expensive. I wouldn't want you to waste your money on a prescription if it does't work for you. I'd prefer you to try before you buy, I do have some samples and can give you a single pill trial. If you take the pill in the office, it should kick by the time you get home. Do you want to try?"
"Sure! Let me have it."
"OK," said the doctor. "Call me if it works for you so I can give you a prescription; or call me if you have some problems."
The man took the pill, jumped in his car, and headed home.
Just as he drove into his driveway, he felt the pill begin to kick in. He really wanted to see his wife.
He went into the house and called out, "Honey I'm home and I have a surprise for you."
The maid replied, "Sorry but your wife has gone out shopping. She won't be back for three hours."
Crestfallen, the man called the doctor, and expressed his concern that the pill would wear off by the time his wife got home.
The doctor replied, "Well, what about the maid? ... if she's willing of course. That will show if the pill works."
The man said "That won't prove anything. I've never had a problem getting it up with the maid."