When Darcy asks Elizabeth to introduce him to her aunt and uncle who are with her touring Pemberley, Elizabeth is aware that he has already assumed that they are people in the genteel class. Elizabeth correctly guessed that Darcy would be surprised to learn that they are her working-class relations from Cheapside in London. He certainly does show surprise when she introduces them, but he quickly recovers, starts walking the grounds with them and converses with Mr. Gardiner. Darcy behaves very gentlemanly towards them and even invites Mr. Gardiner to fish on the estate, offers fishing tackle and points out the best places to fish. Later, when Darcy brings his sister to meet Elizabeth, he even invites Elizabeth and the Gardiners to dine at Pemberley. Darcy's behavior is so changed from what she first saw, so lacking in judgement and conceit that she is absolutely shocked.
Mr. Darcy treats the Gardiners with great civility. First, he asks Elizabeth to introduce them to him. E. thinks that when she reveals to him they are her relatives, he will leave immediately. However, he decides to walk with them around his grounds and converses at length with Mr. Gardiner. He even goes so far as to invite Mr. Gardiner to fish on his property and offers him advice on the best fishing spots. Elizabeth can't believe he is acting so friendly toward her relatives!