Even if he weren't too proud to ask for help, Lydgate knows that there's no way Farebrother could get him out of debt. Lydgate needs a solid thousand pounds to do that.
Lydgate's moodiness about their financial troubles is only widening the distance between himself and Rosamond.
So when he tells her that they should try to sell their house and its furniture to Ned Plymdale and his young bride-to-be so that they can take a smaller house, she bursts out and says it's all his fault for not being like the other doctors in Middlemarch.
Lydgate's angry with her for being so selfish and unhelpful, but he really does feel guilty for having married her when he couldn't afford to give her the luxuries she was used to.
Lydgate goes to Mr. Trumbull, the auctioneer and landlord of Middlemarch, to ask him about arranging a transfer of their lease to Ned Plymdale.
Meanwhile, Rosamond goes to Ned's mother to congratulate her on her son's wedding, and to ask what house they were likely to take.
Having discovered that the young couple was planning to rent a house at the other end of town (since a better house wasn't available), Rosamond feels justified in going to Trumbull behind her husband's back to cancel the request.
She tells Lydgate that evening that the Plymdales have already chosen a house, but not that she cancelled the request with Trumbull to be on the lookout for other potential buyers.
She asks her husband how much money would get them out of trouble, and he tells her a thousand would do it, but that he's not likely to find a thousand anytime soon.
She resolves to write to his uncle for money without telling him.
After all, she reasons, Sir Godwin Lydgate was very nice to her when they visited after the wedding, and his son, Captain Lydgate, had visited them.
She doesn't mention, in her letter, that Lydgate was unaware that she was writing.
A few days later, Rosamond finally tells Lydgate that she cancelled the order for Trumbull to be on the lookout for a buyer for their house, and Lydgate is angry that she did that behind his back.
She decides not to tell him that she's written to Sir Godwin, but asks him not to go to Trumbull again for a few weeks.
This is the state of things between them on the night of the New Year's party at the Vincys'.