"Good Samaritan" joke

A man is having a few drinks at a bar when he looks over and notices a drunk guy passed out at a table nearby. The bartender tells him the drunk is Mr. Murphy and asks the man if he could drive Mr. Murphy home. Being a good Samaritan, the man agrees. The bartender writes down the address and gives it to him.
The man walks over and tThe Donkey "A man walks into a bar and orders a pint of lager on the side of the bar he notices a large jar filled with one pound coins the asks the bartender
"what do i have to do to win the money in that jar"
The bartender replies
"I have got my pet donkey out the back all you have to do is make him laugh and the money is yours"
So the man goes out the back and sure enough he makes the donkey wet with laughter.
the man emerges back into the bar
the bartender amazed asks
"how in gods name did you make the donkey laugh"
"now that would be telling" the man replied" and with that he walked out with the jar of money.
A few weeks later the same man returned to the bar and saw another jar full of one pound coins on the bar he asked the bartender
"What do i have to do this time to win this time to win that money"
the bartender replied
"You now have to make to donkey cry"
so the man went out the back and sure enough the donkey is sobbing his heart out
the bartender is absolutely astounded that the man has done it again and asks him " sir can you please tell me how you did that"
"ok" replied the man
"the first time i came in i whispered to the donkey that my cock was bigger than his"
"the secound time i showed it to him"