The next morning, Mr. Bennet calls in Elizabeth to congratulate her on her upcoming engagement. Elizabeth is stunned. Mr. Bennet shares with her a letter from Mr. Collins in which he cautions Elizabeth not to go forward with an engagement to Darcy against Lady Catherine's wishes.
The exact opposite of Elizabeth, Mr. Collins has no independent will to act outside of Lady Catherine's stuffy social approval.
Mr. Bennet thinks the rumor about Elizabeth and Darcy is hilarious because he is certain that Elizabeth hates Darcy and that Darcy is indifferent to her. Elizabeth fakes a laugh to hide her deep embarrassment about her father's misjudgment. But a small part of her worries that her father might be right and that she has overestimated Darcy's interest.
Mr. Bennet exemplifies how first impressions and prejudices can be so enduring. Elizabeth and Darcy have each changed profoundly, and the Bennets owe Darcy everything. But all of these changes are under the surface, so Mr. Bennet can't see them. In fact, even Elizabeth isn't entirely sure what's going on in Darcy's heart.