Definition: Given a real-life anecdote of a complex ethical situation, generate a suitable title that describes the main event/root cause of the situation. Imagine that the given text is a social media post, and you have to write the title of the post, so the users can decide to read the main text or not.
Input: For a bit of context, my sister is almost 13 and I'm 16. So, as teenage siblings, we don't want to share our stuff if we don't feel the need to. We both enjoy both traditional and digital art. I got a computer for Christmas and my sister keeps asking me to get stuff for her on it. I occasionally get her a few steam games that are $5 or less that she likes (This is out of my own bank account/steam gift card, btw).

She recently broke up with her toxic boyfriend and is now asking me for stuff more frequently. Today she wouldn't leave my room when I asked nicely, so I started to raise my voice at her to get out and she laughed it off like it was a joke. About an hour ago she came back into my room and asked if she could use her tablet to draw on my computer. As I was in the room and not doing anything on my computer I gave the ok. She couldn't figure out how to connect her tablet and went to Google (Again, I gave her permission to do this). After she still couldn't figure it out, she asked to use my drawing tablet. Now I don't like sharing my tablet because, well, it's mine and while she is careful with technology she's not great with putting my things away, so I told her no. She kept asking why not and I gave the shitty excuse of "My cable isn't that great". I would have just given her the truth of "I don't want you to use my tablet" if I hadn't done that in the past and she tells me to give her a good reason. 

I keep telling her no and insisting that my cable is broken, so she takes to trying to find a substitute cable, which doesn't work. She goes back to trying to figure out how to connect her tablet. She figures out that she needs to download something onto my computer in order for her tablet to work. She asks me if she can download it, and I tell her to give me a minute and I'd look at it. I was reading something on my phone and I didn't want to loose my place, so I decided to finish reading and then come take a look. When I told her this she flipped and asked, "Why can't you look at it now?" Again, I've told the truth in the past and she doesn't buy it as if I'm lying or something. I give her the excuse of "I'm really busy looking up something for class right now". She's still pissy at me. We have a fight and she eventually leaves angry. I saw she put my drawing tablet in the middle of my floor once I was done reading (which took me less than 2 minutes to finish). 

Am I the asshole for not wanting her to use my tablet or download anything without me reading it first?

not sharing my drawing Tablet/downloading an art app on my computer