When you’re past a certain age, or paying your own bills, you get to decide who you live with and who you don’t. Maybe you have roommates, but hopefully they’re your friends or carefully-chosen strangers. Maybe you let your friend from college crash there when they’re in town. Maybe you let family stay with you around the holidays. Whatever it is, what matters is that it’s your decision and not anybody else’s. 

Nobody gets to tell you what you can and can’t do in your own home. Nobody has the authority to force you into sharing a space with someone you didn’t anticipate sharing a space with. This is especially true when that person is not your favorite. Let’s say they’re your immature, loud, and messy stepsister. You probably wouldn’t be too keen on sharing a space with her. And heaven knows you shouldn’t have to.