A man walks into a bar...

A man walks into a bar and orders a pint, as he's sitting at the bar drinking he notices a huge jar of money behind the bar, the jar is stuffed full of £10 notes. The man decides that there is easily £500 in this jar, after a while he asks the barman what the jar is for, " Well we have this old donkey tied up out back but he is a miserable bastard and constantly cries" explained the barman, "Its £10 to buy in and if you can make the donkey laugh you walk of with the jar of money". The man decides that it's worth a try so he gives £10 to barman and goes out back and whispers in the donkeys ear. The donkey bursts out laughing, literally pissing its self laughing. The man walks back into the bar takes the jar of money and leaves.
Several months later the man returns to the bar only to see that there is an even bigger jar of money behind the bar. "What's that for?" he asks the barman, "Well the donkey won't stop laughing now, its £10 to buy in again to try and make the donkey cry". So the man hands the barman £10 again heads out back and returns a few minutes later, after checking the donkey the barman sees that it is crying again. Astonished he turns to the man and asks,
"What did you say to make him laugh to begin with?"
"I told the donkey that I had a bigger dick than him."
"And to make him cry again?"
" I showed him my dick."