I have started hanging out with a group of coworkers. Basically one of them who was my friend from before started inviting me and including me in their activities. I would still usually feel like they are just including me to be nice and not because they really like me, but I just went with it. Well now I am starting to realize that this one girl who is part of the group is starting to display some hostility towards me. It's weird, because she will be nice to me sometimes, but when they are chatting together at work and I go over and say something, she will often look at me with this annoyed look and say "what?" I have also noticed that she will often talk to everyone and ignore me. I have been nothing but nice to her, so my guess is that her reason for disliking me is thinking I am dumb or finding my personality annoying. It sucks, because I actually like her and have recently become kind of infatuated with her. And pretty much everyone at work likes her too.

So what is the best thing to do in this sort of situation? I feel really humiliated when I try to be friendly and she treats me like that. But at the same time, I don't want to go back to being a loner and avoiding the work social scene. And if I confront her about what she's doing, I feel like it can only end badly for me, since she is more well-liked than me and it is likely others feel the same way towards me as she does but aren't showing it. What do I do?