Is it a new Vacuum or a diamond?

As I walked in last night from walking our dog I heard my young child excitingly telling my mother in law "we got a new vacuum!" Wow! My mother in law said "your mommy will love her new vacuum!" The tone of my mother in law's voice indicated that she thought I had just won the lottery but in fact the only thing I had won was a new vacuum which is apparently "mine." Although in fact I just used it for the first time and I do "love it" when did it become assumed that when a new household appliance is purchased it immediately becomes the wife's? I am exteremely lucky to have a very domestic husband who I proudly but somewhat embarrassingly admit is more domestic than me at times. He gets right in there with me and helps and cooks and cleans whenever he can and does an amazing job at everything around our house. Yet we refer to our cars as our cars although he drives one and I drive the other. Still when we purchase a new vacuum it becomes mine according to my mother in law. Interesting. You would think I would have gotten a diamond instead of a vacuum with how excited she was with my news of our most recent purchase. Well I had better go-my new diamond calls, I need to use it on the upstairs carpet.