Okay, this is complicated, and I've been getting mixed responses from the friends I've shared with, so I think I need a neutral set of eyes to look at the situation. I'll try to keep this brief, but knowing me it'll be a novel, so be prepared.

Here's the backstory - my sister is 17 now, and I'm 26 (almost). Because of our age difference I helped to raise her in some ways, and as kids we often spent time together. And I swear, I've never loved anyone more than I loved my sister. To say that for most of her life she's been my entire world would be an understatement. She was my everything, we influenced each other a lot when she was younger. She got a great sense of humor thanks to me (a trait the two of us share but neither of our parents does), as well as a love for videogames, anime and other nerdy stuff. Some of my best memories were spent with her, playing games side by side, or her watching me play through something that's too difficult for her, or me helping her beat her first game. 

And then she entered high school (this was a few years ago, when she was 13), and things changed. She suddenly matured a lot, both in terms of her personality and body. She started getting interested in make-up, fancy shampoos and clothes, which I (despite being female) never quite cared about, these things have always been a means to an end rather than something to obsess about. She got her own group of friends her age for the first time (she's often had 1-2 close friends but has never been part of a group). Eventually she found a boyfriend too. And you know what? That's fantastic and perfectly normal. I was a loser in high school, the weird kid everyone bullied and made fun of, but she's a popular girl, a cheerleader and overall highly social. Which is great, and I genuinely could not be happier that she's having fun in school.

The problems started to emerge when her personality shift suddenly made me second fiddle. Obviously our relationship could never be the same as it used to be, she's a teenager and I'm in my 20s, with a job, I get that we wouldn't be able to spend too much time together. But we barely spent *any* time together at all. Every evening she brought along her group of friends to girly scream all night, which sucked considering the fact that I was trying to sleep. Requests to do this less often were rebuffed by both her and my mother (who considers me the disappointment of the family and is beyond happy my sister is turning out so different from me). This ultimately led to me moving out. 

After that, whenever I tried to initiate contact with her I'd usually be rebuffed. Half the time whenever I said hi to her on Messenger she'd leave me hanging on "seen", and when I asked her about it she used the excuse of "Oh, the messages are not showing up for me" (bullshit). Whenever I asked to hang out, either at my place to play something or watch a movie, or maybe hang out at the mall or go for coffee (I try to meet her halfway, interest-wise) she'd say yes, and then when a day before the date or sometimes on the date itself she'd message me saying she's made plans with a friend of hers and won't be coming. I'd invite the family to dinner at my place, and last-minute I'd get a call from my mother telling me my sister doesn't feel like coming.

Gradually we lost touch. The first time this happened we didn't speak for about a year, and us getting back in touch was mostly orchestrated by my mother. She was overjoyed to have me back in her life, and I was too, and for a while things were great! This lasted maybe a month, maybe two tops, and then she was back to her old self again, and the same thing happened, we stopped speaking. And that brings us to our current situation. A few months ago she messages me out of the blue and is like "Let's hang out", so I say sure, why not, olive branch and stuff. We hang out, it's super fun, and she off-handedly mentions that her boyfriend has a D&amp;D group that he refuses to let her into, and she'd really like to play. I say "Don't worry, I've ran D&amp;D games too, I'll invite a few friends over and we can play."

I organize everything, invite her, her boyfriend and three of my own friends to play, and it was without a doubt the worst D&amp;D session I've ever had in my life, mostly because of her. Her character was completely wrong for the setting (she wanted to play Connor from "Detroit" in a fantasy setting), she had almost no usable skills, and despite the fact that a few days prior we went over this and told her to make a paladin with certain skills, even going over the character backstory together, she listened to none of that. Halfway through she completely refused to participate at all, just sat quietly on her phone while the rest of us played. Surprise-surprise, after the fact she whined to her boyfriend about how "left out" she felt, and he happily invited her into his own D&amp;D group. The three friends and I planned to continue playing, and I invited the boyfriend over with us since he seemed to have fun, but he said my sister told him he wouldn't be a real man by her if he went. So he refused. And it's really hard for me not to see this whole thing, with her suddenly getting back into touch, as a plan for her to get what she wanted and couldn't have, namely a place on her boyfriend's group. 

I'm thoroughly disgusted by her behavior in front of my friends and cut contact, and she doesn't try to contact me either (I haven't blocked her anywhere but neither of us write). Very recently I happened to adopt a kitten, the sweetest, most lovable snugglebug in the whole world. My mother came over and fell in love with her, and she regularly comes by to play with her while I'm at work. This week she took my sister along with her, and apparently my sister really loved the kitten. Right as rain, today I get a call from my sister out of the blue saying how sorry she is for the D&amp;D and asking to come hang out. And I wasn't mean, I wasn't rude, but I honestly explained that we're not really friends anymore, we've grown too far apart, and this has been working out for me. It's amazing to not have someone who treats you like you're nothing most of the time, it really is. And she said "Okay, I'm sorry" and burst into tears. 

And now I feel like an absolute ass. Because on one hand maybe she contacted me out of the blue, like before, to get something she wants - namely time to spend with the kitten. After all why contact me now, of all times? She had plenty of time before. Not to mention even if her intentions are 100% unrelated to the kitten, what's my guarantee that she won't start treating me like dirt in 2-3 weeks? After all this behavior is nothing new, she's been doing it for years, and I doubt she's matured enough in just a few months. But on the other, what if this was a genuine attempt for her to try and change our relationship for the better? What if she truly wanted to turn over a new leaf and I shut her down? I'd love to have her as a friend, I really would, but only if she was willing to put in the work to be my friend rather than making me do it all. If she's planning to go back to her old tricks, or just uses me as an excuse to come pet my cat, then I don't really need her in my life. 

I don't know her intentions and this is really the source of my conflict. Should I have given her yet another shot hoping she'd matured and learned from her mistakes? Am I the asshole for rejecting her?