I hate living with my grandmother

I'm 15 and live wth my grandmother and my little sister who is 13 years old and I hate it. My sister gets treated so differently. When i was my sisters age I never even had a phone and was shopping at Walmart and my grandma always says I get more than her when she is 13 with a really nice android and her whole closet is Victoria secret and she complains about everything. I never complain but get yelled at for everything small I do. I miss a day of brushing my teeth I get yelled at. I haven't seen my sister brush her teeth in months. They are yellow! My sister sneaks out at night to see boys and when she asks to hang out with a guy she allowed. And I'm not. I also never sneak out at night. Another things is my sister is always in my iPhone taking selfies. If I could I'd show the the 1,000 selfies of my little sister all over my phone. 90% of the time I'm never on my phone it's so rare. But if my grandma sees me on my phone I get yelled at and either get a lecture on how I'm on it to much or get my phone taken away if she's feeling extra mean. My grandma and my sister claim I'm the mean one when my sister is a brat. When my grandma says no to a shirt at the store she mumbles mean things and complains and when she is alone with me she'd say things like

She's leaving your sister to her own devices. YOU, however, she's putting through 'special training camp'. Ask yourself which sister strikes her (even completely under her own radar) as having the greater potential for being someone of note when she's older thus worth keeping 'straight' and taught self-discipline today. Granny doesn't even care enough about little sister's oral health, note. Not so yours, note-note-note. Granny can probably see her past (wasted) self in you and wishes someone had made *her* pump her mental muscles more so that *she* could have gone on after leaving home to make the most of her truer potential. If you don't care about someone, you don't bother critique-ing them and making them 'work out' harder and have to work really hard for whatever they want than anyone else you know, do you. Favours and special allowances you save for the more unfortunate one, the one that deserves compensating for her 'lack of'. Granny's just got an old-fashioned, seemingly perverse way of showing it and going about it, that's all.