Truth About Deception

There's something eating at my relationship, and I can't help but be afraid eventually this is going to be too much to handle... My boyfriend is still best friends with his first lover. While I know that he's over her and completely faithful, I also know that she is in no way over him. It's fairly apparent to most people--she isn't very subtle about it, if she's trying to be--but my boyfriend just hasn't been able to see it. They spend a lot of time together, more than I spend with him, and I can't help but feel like we're competing for his attentions, constantly. The two of them have known each other for years, and there's such a history there that she seems to come up in every conversation... It's frustrating, so incredibly frustrating. Recently, she and I have been in an unrelated conflict, and he won't take a side... I know that he's just trying not to lose a friendship/relationship, but I hate the fact that he can't back me up. On some level, I feel like I can't ever be the one who's most important to him, and no matter how much we discuss this, nothing ever changes... I'm so jealous, and I hate it, but I can't help but feel angry....