Un PC Jewish joke

Two jews John Goldberg and Alan Goldstein are chatting and one says to the other "John, you are my best friend if I had two houses I would give you one of them" his friend John replies "if I had two houses I would give you one of them too my friend."

Alan follows this with "Goldberg if I had two cars I would gladly give you one of them." Again Goldberg replies "and if I had two cars I would gladly give you one, friend."

Alan then says "John if I had two chickens I would happily give you a chicken." John comes back "f**k off you know I have got two chickens."