An elderly retired couple went to a doctor. The man said, "We want to know if we are making love properly. Will you look at us?"
"Go ahead," said the doctor. They made love. "You are making love perfectly," the doctor said. "That will be $10."
They came back six weeks in a row and did the same thing. On the seventh visit the doctor said, "What are you coming here like this for — I told you that you are making love properly!"
"She can't come to my house," said the man, "and I can't go to her house. A motel costs $20. You charge us $10 and we get $8 back from Medicare."