I have a few suggestions for stopping your cat from eating the fake Christmas tree. First, you can try placing the tree in a location that's inaccessible to your cat, such as a high shelf or on top of a table. Alternatively, you can also try spraying the tree with a bitter apple spray, which will discourage your cat from chewing on it. Additionally, you can try distracting your cat with other toys or activities to redirect their attention away from the tree. Finally, if all else fails, you can consider getting a real tree instead of a fake one, as some cats may be more attracted to the real thing.