If you end up eating the loss, make sure you get his SSN so you can send him a 1099 for the debt forgivness. Maybe you can take some comfort knowing that Uncle Sam won't be so forgiving when it comes to collecting what they are due.
Take the furniture, sell it, eat the loss, learn the lesson, call it square.
Did you not find it odd that your grown brother could not finance his own furniture? We shouldn't buy what we can't afford. **** my credit is sterling and I never owed a dime on furniture.