Being entitled is not something excusable. Is a reality that being nice can assure you nothing in life. So being kind is actually something you do just because, not expecting even a thank you. That's why, in this case, it is a good thing that this person decided to let the friend stay in their guest room just as a kind act. Because if they were expecting a thank you or anything in return, then they would need to keep waiting. This friend thought that a great retribution for the favor was to speak ill of her to her friends while being in the same house, knowing that the resident could have listened and taken offense at that. What's even worse is that she got mad at the homeowner for speaking up for herself when the friend was saying horrible things about them. The friend said that the homeowner was trying to embarrass her. To which I can only think: wouldn't it be the other way around? The friend was the one who made the situation difficult and uncomfortable. Why would you get offended that they tried to defend themselves?
This is just another example of what not to do, and that is not to expect anything in return when doing a favor. You can consider someone a friend, but not fully know them. I'm pretty sure that this homeowner had no idea that by opening their house to a friend, they would end up discovering that the friend was actually an entitled, ungrateful, and mean person who they shouldn't be friends with. I'm sorry for this person who put their house at their friend's disposal, only to realize that they weren't even a good friend in the first place. The friend didn't deserve any of that. They were so entitled that they concentrated too much on judging the room instead of enjoying the favor. I hope the homeowner makes better friends from now on. They do deserve better.