Whenever I'm in bed with my girlfriend I don't want her to have her stuffed animal there.
Why do you have an issue with that?
She'd be cheating on me in my opinion.
You need to be less controlling and not tell her what to do. It's not harming anyone when she does that.
I have been hurt by cheating in the past and I don't want to be cheated on ever again. The bear has to go!
It sounds like you have some very unresolved issues with cheating if you are jealous of even a stuffed bear. You should speak with your girlfriend about these feelings, because you should not be telling her what to do when it comes to a stuffed animal.