I'm Part Of A Group Of Friends But I'm Always Left Out, Why?

In high school I had a group of friends who would drink&party and that wasn't really me, so I kinda "left" their group and became close to another group. In this group, there are 4 of us. I've only been friends with them for about 2 years now, and they've been friends for 5 years.
Anyway, we all left highschool pretty close and now we're in college. Two of them in the group treat me like part of their group&i get along with them so well.
However, theres one girl in this group who is really nice, however, she always seems to treat me like I'm still not part of their group. For example, she invited the 2 of them for a sleepover, and never told me - I only found out after asking one of the two girls. I let it go as I realised maybe it was because she didn't have enough room in her house, but anyway in college I thought me & this girl could be closer, as we catch the same bus, but even then I feel like we only talk about her.
She went on vacation & bought us all bracelets, but gave it to us seperately. I was so happy that she got me something, it made me feel as though I was finally part of her group (as she acts like the group leader) until one day I sat at lunch with the two other girls and saw that they had identical bracelets. I said to one of them that I liked their bracelet, and she said it was from Y (name of leader) and I realised that she bought them both identical bracelets, and not me. It was almost as if they all have friendship bracelets and I'm just left out.
When Y isn't at college I feel as though I'm listened to more, like the other two treat me as their leader, and will follow me about, but I'm ok with that. But as soon as Y is in, we do everything she does.
One of the two girls told me that she finds it hard to talk to Y, but finds its easier with me.
Don't get me wrong, I think Y is a nice girl but things she does make me feel as though she still doesn't see me as an equal.
Basically, I just want maybe some advice or answer to why this happens? Is it because I joined their group late, although we've had many memories? I'm unsure. My mom says shes a bit of a user, but I don't really know.
if you have any ideas why this happens, don't hesitate to answer thank you :)
zebraprintnails zebraprintnails
18-21
1 Response Sep 9, 2012

****EXTRA BIT***** When we first started high school, I never really spoke to Y. A girl I was friends with was close to her, so I started hanging around with Y's group (this didn't have the other two girls btw) and she used to always ignore me. I never knew why until my other friend told me that Y said that I used to bully her in freshman year, when I didn't even know her until sophomore year? I always feel like Y hasn't let this go, even though I never called her or anything like that. Shes never told me that she was "call" her, maybe she can't let this go?