So currently my gf (23) and I (24M) live together. I recently got a high paying job and talked with my brother about buying a house. Now my brother and I both hate cats. We think they're messy, destructive and annoying. When I talked to my brother about my gf living with us he didn't want her to live with us at first but I told him we were a package deal so he eventually relented. However the deal is she can't have her cats. She is saying she would rather be homeless than to give up her two cats. I keep telling her she's being unreasonable and to just give them to a shelter. I have also tried to be accommodating to her by telling her she can keep the cats in her room (she agrees to this) but she still needs to convince my brother to change his mind and let her keep the cats just in her room. They've already had one conversation and he just kept repeating how he doesn't like cats. Now she wants to give up after one conversation with him and I keep trying to tell her to continue asking him because maybe he'll change his mind. She's also called me an asshole for even asking her to give up the cats in the first place.
Also a quick side note she was recently diagnosed with POTS and an autoimmune condition so I take care of the cats on the days she's not able to get out of bed.
TLDR
I want to buy a house with my brother and I asked my gf to get rid of her cats so that she could live with us.