A female gorilla in the local zoo was becoming increasingly belligerent.

The vet realized the gorilla was in heat and needed a mate. He called other zoos to find her a partner but none were available. The vet noticed that the gorilla grew calmer whenever a tall, hairy, muscular, but not-very-handsome keeper entered her area. Being an adventurous fellow, the vet made an outrageous proposition to the keeper. For a fee of $500, would the keeper consider spending a little “quality time” with the gorilla purely in the interests of research, of course?
The keeper, also an adventurous fellow, thought about the suggestion, and after a few minutes agreed subject to three conditions.
"First," the keeper said, "Absolutely no kissing."
"Fine," said the vet.
"Second, no one must ever know - if this gets out I'll kill you."
"You have my word," said the vet, "And your final condition?"
"It's just," said the keeper a little awkwardly, "Can I have a couple of weeks to raise the $500?”

Comment: Did you know that laughter causes the pituitary gland to release pain-suppressing opiates. A number of studies have found increased pain tolerance in those who supplement medical treatment with humor.