How to deal with this aggression?

[IndiReloaded]

Love how you are making it her problem and not your BF. Typical catty behaviour. She may be a bitch but you are getting angry at the wrong person. Maybe you are afraid that if you actually call your BF out on his behaviour that he will breakup with you and run to her?

Not like you'd be losing much if so. Hmm.

[Boisdevie]

I suppose a threesome is out of the question.

I am sat here laughing at the keyboard. Nice one mate.

[HeartIsAching]

Newsflash: This is your boyfriend who is choosing to keep her in his life while he disrespects you. It's not his female friend that is causing this rift between you and he. When you realize and accept that fact, you'll be able to tell him that it's no longer acceptable to you that he and his family would much rather have her at the family functions than you and you'll simply leave for someone who doesn't balance two women on equal par.

This. Seriously, this is it in a nut-shell.

YOUR BOYFRIEND is choosing to keep her in his life against your wishes. She isn't somehow forcing him to do it. He knows you don't like it and is doing it anyway - ergo, she is more important to him than you are. Period. You MIGHT get him to realize differently if you break up with him, but even if that doesn't back-fire on you, would you really want him under those circumstances? Seriously?

It's time to walk away, young lady.