Why does pip feel uncomfortable when joe comes to visit?

Class consciousness is the major theme in Great Expectations. Pip is embarrassed by his dear friend and brother-in-law Joe's country ways after Pip's own rise to the status of Gentleman. And he is, rightly so, ashamed of feeling this way, though unable to feel--or act--otherwise. Joe sees this and, being the big-hearted and insightful man he is, goes away so as not to trouble Pip's conscience. He shows himself, at this point in the story, to be the better man.