just STOP TALKIN` TO HER FACE THEN!!
ignore her. if she can`t get over what you did AND YOU SAID YOU WERE SORRY RIGHT? just stop talkin` to her if she`s acting so much like a b!tch..
there IS something called FORGIVE & FORGET but CLEARLY your friend has NEVER heard crap about it. it`s not like you`re going to continue what you did, right? you stopped.
i mean....what i think is....your friend is treating you like some WHORE that messed with this guy which you didn`t do INTENTIONALLY.
who cares if she doesn`t blame the guy?? doesn`t that other girl like him or something?

i don`t know the story behind that, but why should she side with the guy thinking HE`S innocent and you`re the guilty one!?
don`t worry. you don`t have to prove that you were right to those kind of people. as long as you know you`re right. `cause i don`t think those girls are going to admit they`re wrong at all..b!tches..