A couple went to the doctor’s and asked him if he minded watching them have sexual intercourse. The doctor was used to odd requests so he agreed and after it was over he charged them ￡35.

The following week they returned and asked him again. He assured them that there was nothing wrong with their technique, but they were so insistent that he relented.

Again, he charged them ￡35. However, when they came back a third time, the doctor became very suspicious.

“Why are you doing this?” he asked.

“You’re doing us a big favour, doc,” they said. “I’m married, my girlfriend lives with her mum, and the hotels are very expensive. If we come here it only costs us ￡35 and I can claim it back on my private health insurance.”