May be she likes her furniture . No one knows for sure. But I saw many situations when one of the partners is just living of another without giving it a second thought without any reason other than she/ he is allowed to do that.
And here comes resentment. I don’t think OP shows any mean personality . I can see him
Being upset that on top of him covering all the expenses his partner comes up to him with such a suggestion.
One thing would be if OP himseld offered this to her. He would say something like: hey I have this guest’s house just sitting there . Why don’t you use it as your income since you lost your income by moving in with me. But it’s obviously not the case. The major factor is that OP completely took over her living expenses including food.
She did loose her Airbnb invome but she gained much more of not worrying about how to pay her rent or food.
Op even considering 30% . What he is upset about that she wants half of what that place will bring and judging by the fact that it’s a lake house it could be quite a sum .
I am sure there was an argument when she told him something : but I am furnishing the house . Which OP does not even considering any significant contribution at all. And he is right. I furnished 4 bedroom home from
OfferUp.com for less than 2000$.
The main point here is that it’s his house not hers and he can do with it whatever he wants . I agree with him that what she wants is too much. And she only demands it because of her relation to OP.