On a visit to a zoo Gary is looking at a rather large gorilla when the zoo keeper approaches him and says "This gorilla is on heat and we urgently need someone to have sex with it - would you consider shagging it for £500 ?"
Gary says "Yes - I will, subject to 3 conditions
1st. I'm not going to kiss it
2nd My family must never know
and 3rd. You need to give me a couple of weeks to get the cash together"