Pushy overbearing grandparents, help?

Morgan

My boyfriend was raised A LOT different than I was.. his parents are caring but take more of a tough love approach, they also have a lot more money than my family did so I’ve noticed they start to use it to get even the smallest baby decisions swayed in their favor.. like for example, offering money to contribute or even going as far as to buy something they want the baby to have even though they know me & my boyfriend don’t want that specific type or brand of something for the baby. Anyways they are really opinionated & don’t really care who’s feelings get hurt when they are speaking their mind. They have a sense of entitlement to the baby already & he isn’t even here yet. My boyfriends mother is constantly addressing the baby as “My little baby Emmett” ever since she found out his name & idk if I’m being unreasonable but it really irritates me as it isn’t “HER” baby.. it’s my boyfriend and I’s son. It just feels intentional.. anyone have any advice on dealing with overbearing (sometimes rude) grandparents or how to assert your role as the parent to them? Possibly without starting a fight?