@emMeBi86 No. Just... just no. Look, she may be her "friend" or whatever, at this point that's fucking ambiguous, but you gotta realize, no matter how well you think you know someone, that doesn't mean they are entitled to inform you of EVERYTHING that goes in their life. Privacy is a thing for a reason, and its a crime to violate it for a reason. An no, it's not partially the protagonist's fault, because, maybe, IDK, telling your best friend, who's a girl, that you are in a destructive lesbian relationship that may or may not be bad for you is not the easiest/comfortable topics out there. Not only will she have to deal with the judgement, which many don't take easily, for the same sex thing, but for the double (heck, triple even) immorality of the act.
If Aya fucks up her own life and her own sexuality because of this, that'd be sad, and "friend" would also be sad, but trying to white knight yourself into the situation without even consulting the person? Fuck you, you hypocrite (The friend), don't do that. That's not what a friend or potential love interest does.