Tony Lumpkin is the older child in the Hardcastle family. He is Mrs. Hardcastle's child by her first marriage. He is a spoilt child, thanks to his mother's permissive ways towards him. Obviously, Mr. Hardcastle would have been of help in bringing up Tony Lumpkin properly, but his wife will not allow it. He enjoys making practical jokes.
In the first place, Tony loves to spendhis time among the commoners in the village tavern. He is there when Young Marlow and Hastings come looking for their way to the Hardcastles. Tony takes this opportunity to pay his stepfather back for calling him names all the time. He misdirects the visitors, describing the Hardcastle home as an inn. This deception brings about exciting incidents in the plot. Young Marlow and Hastings go to the Hardcastles' house thinking it is an inn and the many mistakes of that night unfold, including the first meeting between Kate and Young Marlow.
Secondly, when Tony learns that Hastings means to elope with his cousin, Miss Neville, whom his mother has been busily courting for him, he is more than willing to steal her jewels for her to enable her elope with Hastings . Tony succeeds in this, and gives the jewels to Hastings who in turn gives them to Marlow for safekeeping. Mistakenly, Marlow hands over the jewels to Mrs. Hardcastle. As a result of this, Mrs. Hardcastle decides Miss Neville must go and live with Aunt Pedigree at Cracksku! Common.
Again, it is Tony Lumpkin who comes to the rescue of the lovers. He drives the carriage carrying his mother round and round pretending they are on the way to Aunt Pedigree. They end up close to where they set out from and later Hastings has to make a formal proposal to Miss Neville to settle matters.
To conclude, Tony Lumpkin seems to be the pivot around which the plot of the comedy develops. Any time he appears, a new event begins or a situation is saved.