Last Name

How do you pick whose last name is used after becoming life partners? I’m the sub and feel like I’m the one who’s expected to change my last name but really don’t want to change it because it would cause chaos with a lot of my very religious family members who haven’t even been told about my orientation (let alone about my partner).

Is it appropriate to just keep our own last names the same to keep our lives easier and more private when dealing with my family? I don’t intend to tell around 75% of my relatives about my life because I’d rather be selective and safe than be cast out by everyone and become an annual angry debate topic at family gatherings.