A married couple at the Zoo walks past a gorilla enclosure.

Says the woman: 'Mark, do you know that gorillas are the only animals which resemble men in their behaviour?

Look, seeing that no one is looking, I'll expose one of my breasts to it and see how horny it gets just as men do.'

Mary then exposes one of her breasts, and, sure enough the gorilla gets excited and grabs the bars of the enclosure as if it wanted to break free.

'See,' says the woman, 'Now, I know why you react the way you do; men can't control their animal instincts just like gorillas can't.'

Says Mark: 'Now expose both breasts and let us see what happens.'

The woman exposes both breasts to the gorilla and itgets very excited and is nowdesperately trying to escape from the enclosure.

Says Mark: 'This is incredible, now, pull your skirt up, turn around and expose your bum to it and let us see what happens!'

The woman pulls her skirt up, turns around with her bum to the gorilla, which by now, was extremely aroused, breaks free from the enclosure, grabs the woman and starts yanking the clothes off her.

The woman yells: 'Mark , what do I do now? Please, help me!'

Mark replies: 'Now, tell him you have got a headache... and let's see if gorillas and men are the same...'