When Lomov asked for the hand of Natalya Stepanovna in marriage, Chubukov reacted with great joy and excitement. He exclaimed "By Jove! Say it again — I didn't hear it all!" and embraced and kissed Lomov warmly. He shed tears of happiness, saying he had always loved Lomov like his own son and had been hoping for this proposal for a long time. He also assured Lomov that Natalya would consent, saying she was "like a lovesick cat." He then rushed off to call his daughter.
Source: The Proposal, Chapter 9
The examiner expects you to cover three aspects: Chubukov's initial suspicion (he thought Lomov came to borrow money), his sudden joyful reaction on hearing the proposal, and his emotional response (embracing, shedding tears, giving assurances about Natalya). Note the contrast between his aside ("He's come to borrow money. Shan't give him any!") and his outward joy — this hints at insincerity, which is worth mentioning if marks permit.