So for some context I have a twin sister and we get along most of the time but every now and again she'll ask me to use my drawing tablet so she could make some art. Last summer she asked me so she could make some art for people on Twitter. I said sure and thought it would only be a few days. But she kept it with her nearly the entire summer in her room. About half way in i asked about the art and for the tablet back but she says no and that she's almost done. Sometime at the end she finally gives me back my tablet and thanked me. But sometimes she'll ask me to do something or ask for stuff such as going to the store to get her stuff. If I say no she'll whine and act pretty bratty because I'm not doing what she wants.

Fast forward about 6 months and it's the middle of January. I was at home alone for awhile relaxing and on my laptop on a weekend day. When my little brother walked in I saw my sis then walk in to dining room where my laptop and tablet are. (keep in mind my laptop is about 1,000$ and the Tablet cost 80-90$ and she has no way to pay me back) She walks right up to me when i stand with my laptop open but doing nothing. Not even a minute in the house and this is how it goes.

Cast.

Me: Me TS: Twin Sister

TS: Hey bro can i try out your tablet since it's fixed now? You're not using your laptop.

ME: I'm sorry but I just got up and i was going to do laundry.

TS: Cm'on there's nothing going on.  
I sit back down and log out of my profile so she can't get in. She huffs and starts to walk away clearly angry about not getting to use my laptop.

Me: Wow entitled much?

She gets real pissed off at me because of what I called her and then pushes me away from her while still grabbing my shirt hard. After that she storms up the stairs.

I realize that I shouldn't of said that to piss her off more but there was one time where she called me an Asshole for simply not doing something for her.  
People of Reddit was I the asshole?