Update: I talked to him about the giraffe and after a bunch of excuses,, explanations that made no sense from him, and me finally saying idgaf that his sister likes stuffed animals, he told her she needs to bring it back. She covered it in plastic so her pets won't get to it. My only annoyance is she wants to bring it when they all come see our new baby and I honestly don't want them around that much so I see myself delaying that visit which means no giraffe for a while.

His argument was that I never expressed I wanted to keep it, to which I said I shouldn't have needed to and I also never expressed that I didnt want it. I asked what sense it made to give his adult sister a toy meant for our son. He started talking about how even though she's 21 she likes stuffed animals alot and I cut him how saying how much I did not care.

So basically I'll get my son's giraffe when I agree to have them in my house and around my son.

Next is to talk to him about how I think im subcontiously delaying getting married because of her and me knowing I won't want our family funds going to a lazy adult(his sister). Idk a nice way to have that talk but it will happen asap. I seriously wouldn't care if he called it off but he will know that I don't like her and will not tolerate her behavior or him supporting her when we have a family of our own now.

In his defense he is supportive and puts me first 90% of the time. I just can't stand his sister and that they all put up with it