She has done nothing wrong. You only have yourself to blame for this.
You fancy her but you've never expressed this or made a move on her. She see's you as a guy friend. This is the typical friend zone story.
So what if she has another guy friend and she's doing the same thing with him? How is this disrespectful? If you were sexually exclusive with her then yeah it would be disrespectful, but come on man, if you've never made any moves or got this girl into any other zone other than the friend zone then how is she supposed to know how you feel about her?
And now your getting jealous because really you wanted to stick your dick in her but never have, and she's starting to hang out with other guys. But for all she knows you are just a friend, whether this other dude is her friend or if she see's him as romantic potential or not is irrelevant and at this moment in time you don't have any say in that whatsoever because you made it that way.
One thing is for certain. If you start being bitchy about it and crying because you never made your move. You are never going to fuck her and she will do stuff like this and fuck some other guy eventually. Pick up 101 is not to friend zone yourself like this, all these things you've been doing together is what friends do so it's no wonder you have that sort of relationship with her. If you'd have framed it as a romantic and sexual relationship from the start you would not be having this problem.
There are a few ways you can get salvation from this and still boink her. But honestly man it's going to be tough. The first thing you need to do is accept you are in the friend zone position right now. Do you understand?
A little comedic addition...
https://www.youtube.com/watch?v=ZHZsleyKons