How do I ignore someone?
I have to share a room with my sister temporarily, (like a year) and she's nothing but rude. she gets mad over the stupidest things. like if I'm talking to her while she's texting, shes incredibly bossy, She makes the room a mess but says its my fault, she never cleans up after herself and when I complain to her about how I am always having to do everything she says something like "you volunteer! If you didn't do it eventually dad will make someone anyway." and I know my dad likes us to do things without him telling us. also if I do something wrong she runs to my dad and complains and basically starts backstabbing me. he doesn't do anything about it. and after she does that she starts telling everyone she knows about how horrible I am and how she feels bad for any husband I get. Then over the next few hours she acts like nothing happened and is suddenly not mad at me and thinks we are best friends. I can't tell her anything because she tells my dad sooner or later yet again she thinks she can go around telling me her problems. I think if my dad knew about all the things she was doing behind his back, their bond would be ruined. so unlike her, I don't tell my dad about all the things she's done. I wish I could just stop talking to her but that's nearly impossible. And I wish this karma thing that some people believe in was true so she could get a taste of her own medicine. I don't know what to do anymore.