Over the past few months I've gotten to know this girl that I'm really into.. we have a lot of thing in common, and seem to have a really good connection. Over the past few weeks I've let her know I'd like to be more than friends, we go out together, hold hands sometimes, and generally have a great time together. When I've asked her about stepping things up, she generally tries to put me off, she'll tell me 'we can be together later' or 'i just don't want to get involved right now'. So it seems she wants to just be friends and not get involved romantically. All in all I think she just wants to be friends, and I respect that. But other times she talks about us moving in together at some undetermined point in the future, and I'm thinking to myself 'wtf???'
Anyhow, today we make plans to meet for lunch, and at the last minute she tells me she's bringing along a guy friend. I'm like 'okkk that's cool..' but to myself thinking that it's extremely rude and inappropriate to invite someone else like that at the last minute. But I let it go. From the moment we meet up to eat there's tension between me and the new guy. I shake his hand, and he's kinda just looking back at me. He watches me and her looking like he's trying to gauge our relationship. Dinner ends up being very quiet and awkward, very little conversation. I try to chit chat with them, without probing or asking anything like, how do you 2 know each other? But inside I'm burning jealous. When we're all leaving, he asks her what she's doing tomorrow, and she says she doesn't have plans. I sit quiet, shake his hand and we all take off. I'm not her boyfriend, so there was really nothing I could do about it.. if she wants to see him she's gonna see him. But she knows how I feel about her and makes me sit through that? I tried my best to act like nothing bothered me, but it had to have shown through. We have plans to go out tonight with a couple of other friends, and as I drop her off she says she may have to do family things and she'll let me know what's up later.
What am I supposed to do? Why did she put that other guy between us like that? It wasn't remotely fair to me at all.. if I act jealous I'm a insecure guy, if I do something and tell him to back off, what ground am I standing on? We aren't officially dating. How would she feel if I had decided to randomly bring another girl to lunch with us?? I'm bad at expressing how I feel, and I should have told her exactly what I felt, but I didn't simply because I didn't wanna look insecure. This is so frustrating, can someone please give me some advice on how to handle this? I want to have a frank discussion with her about what we are doing together, but at the same time I just want to quit talking to her altogether, because we've had that conversation before.
Btw I'm mild autistic, and she's aware of this. I have a very difficult time interpreting things in social settings, and I feel like she's probably just tired of dealing with it. Is this all my fault?