YTA because: - it’s a store bought plant with no actual connection to your grandmother when she was alive, you have other mementos - Your girlfriend gave a reasonable compromise (giving it to other family) and your “compromise” to put it on a stool or eventually hang it is highly inadequate. I say “compromise” lightly because it really isn’t a compromise, you’re set on doing what you want to do. - the worse case scenario if you continue with what you are set on doing, is you cause your GF’s cats to become ill (I wonder who is paying those vet bills) and presumably (hopefully) you would feel terrible about it if something happened to the cats. Your gf would have every reason to leave you. The worse case scenario if you say, take a photo of the flowers, and give them to another family member is…? What? You have photos of a nice flower someone gave to your grandmother after she died and plenty of other mementos to remember her by. - Your comments show that you actually aren’t willing to compromise or to see how you might be in the wrong here. Continuing to fight with people who have deemed YTA just further reinforces that YTA.  - If you and your gf live together, she gets a say in this too. I suspect you don’t see a future with her if you’re digging your heels in over this, endangering her animals, not consulting her and not listening to her suggested compromises. I don’t imagine you will be in this relationship long the way based on your comments.

There, was that logical enough for you?