Well the lyrics do say "I see you, you don't see me, I'm your one true friend" which could mean that they're sick of getting treated like shit from whoever and it's like their closer to the end of their rope and are this close to leaving them altogether. And as we all know leaving friends is never easy - so maybe the person in the song would never leave them no matter how much they say they will. But that's just my take on it.
Incidentally...Is "Red" about a girl who's been murdered?
Actually, I guess I'm really curious about the chorus, "Take me where the posies die, I feel dead again..." That seems like such an odd thing to say, I was wondering what it meant (or if that's what it really says).