The maid announces the arrival of Lord Illingworth, who forces himself past the doorway and into the house. He approaches Mrs. Arbuthnot, telling her that he has resolved to provide financial security and some property for Gerald. Mrs. Arbuthnot merely shows him Gerald and Hester in the garden and tells Lord Illingworth that she no longer needs help from anyone but her son and his lover. Illingworth then sees Gerald's unsealed letter and reads it. Lord Illingworth claims that while it would mean giving up his dream as a foreign ambassador, he is willing to marry Mrs. Arbuthnot to be with his son. Mrs. Arbuthnot refuses to marry him and tells Lord Illingworth that she hates him, adding that her hate for Illingworth and love for Gerald sharpen each other. She also assures Lord Illingworth that it was Hester who made Gerald despise him. Lord Illingworth then admits his defeat with the cold notion that Mrs. Arbuthnot was merely his plaything for an affair, calling her his mistress. Mrs. Arbuthnot then slaps him with his own glove before he can call Gerald his bastard.