My best friend is leaving for a guy.

Okay so here's the situation:
My friend recently met someone who she is interested in, and even though I have no problems with the fact that she likes him or that he sometimes sits with us at lunch, I do have a problem with the amount of time she spends with him.
When she first met him, she still mainly hung out with us and wouldn't ditch us for him if she said she'd stay with us. Now, she's ditching us for him, even though she has said in the past that she would never put a guy before her friends.
If that's the case, what is she doing now?

Also, we both got invited to a party and she asked if she could bring him, I asked if I could bring one of my friends and got told I couldn't. There was going to be hardly anyone I know at the party, so I skipped it because I was feeling uncomfortable with it. I don't really want to be sitting alone, left out, with nobody to talk to while she goes off with this guy and his friends.

I've been out with them before, and I felt seriously uncomfortable because they paid hardly any attention to me. It felt like I was just there to make up numbers since there were 2 guys and my friend, neither this guy or his friend spoke to me at all. They only talked to each other and my friend. To be honest, I was wishing for the night to be over before it had begun. I would have preferred to be watching TV or something than feel like that.

I don't know, maybe I'm a little jealous of the time she's spending with him, but I'm too scared to tell her that I'm feeling isolated from the group in case she decides that she doesn't want me around anymore. I feel as if I can't even talk to my other friends about it in case they tell her about it. What do I do?

 

You do exactly what you're afraid to do. What risk are you running? She doesn't have the authority to exclude you from a group of friends, and in that context it doesn't matter what your friends do or don't say to her. You're not escaping it by putting it off, you're only letting it stagnate; you need to know where you stand now so you can make a decision now.