Lady Windermere and Lord Darlington are aristocratic friends. In the beginning of the play, their friendship is bound by puritanical values and Victorian codes of conduct. Lady Windermere is the enforcer of these behavioral codes. Lord Darlington sometimes breaches acceptable protocol in an attempt to establish a more intimate relationship with Lady Windermere than is acceptable. For example, during dinner, Lord Darlington showers Lady Windermere with compliments. The Lady expresses his discomfort with his stream of compliments, as it is not appropriate for a married lady to accept so many compliments from a man.
As the story progresses, Lady Windermere learns that her husband may be having an affair. She confronts her husband to discover the truth. Instead of taking her concerns seriously, Lord Windermere's husband makes a mockery of them by inviting the other woman to Lady Windermere’s birthday party. The Lady becomes increasingly distressed. Lord Darlington offers her comfort and support, but also starts to make quite obvious romantic overtures to her during this state of vulnerability.
Lord Darlington and Lady Windermere eventually share a romantic liaison, but it is short-lived. They remain close friends thereafter.