Lydia has two other suitors: Bob Acres (a somewhat buffoonish country gentleman), and Sir Lucius O'Trigger, an impoverished and combative Irish gentleman. Sir Lucius pays Lucy to carry love notes between him and Lydia (who uses the name "Delia"), but Lucy is swindling him: "Delia" is actually Mrs. Malaprop.
As the play opens, Sir Anthony arrives suddenly in Bath. He has arranged a marriage for Jack, but Jack demurs, saying he is in love already. They quarrel violently. But Jack soon learns through the gossip of Lucy and Fag that the marriage arranged by Sir Anthony is, in fact, with Lydia. He makes a great show of submission to his father, and is presented to Lydia with Mrs. Malaprop's blessing. Jack confides to Lydia that he is only posing as Sir Anthony's son. She annoys Mrs. Malaprop by loudly professing her eternal devotion to "Beverley" while rejecting "Jack Absolute".