I (25F) might be having a talk with my sister (27F) about our relationship.

Hi everyone! I never thought I’d be posting in this sub, but here goes.

My older sister and I have always had a strained relationship, at least from my perspective. Growing up, she was like a third authority figure in our house, aside from our parents, and was sometimes a bully. We would fight, sometimes getting physical, and she was verbally and emotionally abusive towards me in the past (tbf, I wasn’t much better in these instances, so it wasn’t one-sided). From what I can tell, our fighting and relationship was… rougher than what most people have with their siblings.

Fast forward to now, and she’s moved out and I’m finding my footing since finishing college. Our relationship hasn’t gotten too much better, but we don’t physically fight. However, she can still be a jerk to me and it feels like she doesn’t see me as an adult. She scolds me when she perceives something I’m doing is wrong, and it feels like she speaks to me condescendingly and is patronizing.

An example from yesterday is when she, her fiancé, my mother and I were waiting for Dad to finish setting up the fire pit for s’mores, and I started snacking on the chocolate (already broken up on a plate). She snatched the plate away after I did this twice, saying “enough already!” It wasn’t the fact that she didn’t want me eating the chocolate (I’ll admit it’s poor form when we’re still waiting for the fire to be ready), but more the fact that it was so… demeaning. Not only could she have been nicer (like say “hey, don’t eat the chocolate just yet,” for example), but was it really necessary to do such a thing in front of the others? It’s never a matter of pulling someone aside privately with her; it’s always been then and there. (I ended up calmly walking back into the house to listen to music to calm down, and it worked.) Though when I brought it up later and was trying to explain how I felt, her apology amounted to “I’m sorry you felt that way, BUT,” and just… that’s not a real apology! She argued that she was being direct, and that I’m in control of how I feel. Which, yes, we’re in control of our emotions, but I’d say I’m still valid for feeling that way and being upset she doesn’t see my perspective.
I know it’s a minor anecdote, but it’s multiple instances like this throughout our lives, and I’m tired of it. I feel like she doesn’t consider me an equal. I sent her a text saying as much (“I wish you saw me as an equal”), and her lengthy reply was to explain that she finds my attitude insufferable and that she does see me as an equal but is amazed that I “act out the way [I] do.” She says it’s exhausting for her.

Here’s the thing, though. From where I stand, it feels like she’s the one who constantly wants it her way. She’s short-tempered, and I was her punching bag (literal and metaphorical) growing up. Nowadays, I try my best to be civil and neutral, but that falls apart when she visits. She’s constantly talking down to me, and doesn’t seem to care when she does this in front of others (like I said, it’s never a private conversation).

On the other hand, from what I can tell, she seems to think I’m immature and childish. I can’t read her mind, but I think she thinks I’m spoiled and bratty. It would be easy to say it’s all in reaction to her, but sometimes I’ll passive aggressively pick fights if tensions have been building, so her seeing me as a brat isn’t entirely without merit.

So, why I’m here is to ask for advice. In her text, she’s said that she’s willing to have an adult conversation about this if I am, but if not, she’s willing to continue “as is.” I don’t know how to go about this, because would I like to have a loving relationship with my sister? Yeah, I guess that would be nice. But we’re completely different people, and having her around makes me irritable and anxious. I don’t feel like she takes me seriously, and I don’t feel comfortable dropping my guard around her. If my earlier attempt at a reasonable conversation is anything to go by, I’ll be talked over, ‘corrected’ on what happened,’ essentially belittled for expressing how I felt, and made to feel stupid for wanting a proper apology. If that happens again, I’d probably get upset again and thus ‘prove’ her point that I’m immature.
I feel like a bad sister for saying this, but I’m at the point where if she were to disinvite me from her wedding, I wouldn’t feel anything, aside from maybe indifference. I want to care, but that opens me up to being hurt further by her.

What should I do, and how should I navigate this conversation? Is there any way to prepare for it, and is it possible to bring up mu grievances without sounding accusatory?

TL; DR: my older sister and I have a strained relationship well into our 20s: I think she’s condescending, she thinks I’m immature, and this has a negative impact on our relationship. I am seeking advice on how to discuss this with her.