I'm just curious (it's not an answer) But why does her best friend make her cry? Is it because she/he is telling her the truth? What makes this person her "Best friend"? It's hard to find Friends who would tell you the truth at your expense.. As shitty as that sounds, i believe GOOD friends should be 100% honest. Even if it hurts.

It sounds like your girlfriend is a absolute sweet-heart! Someone who is easily taken advantage of by some pretty slimey people... I despise those types of "best friends"! What would be the most ideal thing would be for her to finally get fed up with her bestfriends crap... and cut her off! I doubt this happens soon... Considering how nice your GF is... But sounds like you need to have a serious talk with her! Show her examples of everything awful her "bestfriend" has ever done to her... (maybe start jotting these down in a notebook, to later show your GF) Hopefully she will begin to see... It took me a while to truely accept that my "friend" was really not that great of person... And after years of having a relativlty good friendship we are no longer friends... and I happen to like it sooo much better!! She will def. feel automatically de-stressed!!! Try your best to limit your GF time with her "friend"... without being controlling ..or course... GOOD LUCK!! :)

There's a balance between being open (allowing ourselves to care about others) and having healthy boundaries (not letting others walk all over us). When someone has a shortage of openness, they have a hard time connecting and making good friends. When someone has weak boundaries, they tend to get stepped on a lot, especially by those who are domineering and controlling. Both of these problems are really self-esteem issues: having a healthy ego allows one to both connect with others and push back when pushed upon inappropriately. The main issue with weak self esteem is beliefs about oneself inherited from the past: conditioned / automated / deeply embedded ideas about who you are, formed without awareness... typically negative. Many people have varying degrees of "I'm not good enough", "I'm not lovable", or some other "I'm defective" beliefs. In order to make real progress with self esteem, it's necessary to bring awareness to these beliefs and challenge them: to see that they're like a tape recorder playing the same song over and over again: somebody needs to wake up and push the STOP button. Typically, it's necessary to see and interrupt these thoughts over and over again: because they're really mental habits, the habit has to be broken just like you would break any other habit -- remain vigilant, and challenge them every time they come up. With time, the conditioning fades, and what's left is freedom: a natural, spontaneous recognition that "hey, I'm not really broken after all". That provides the foundation for saying "no" to an abusive friend, as well as helping with many other self-esteem related problems.

There is nothing you can do other than express displeasure with the friend and try to tell her why her abusing her best friend is wrong. Frankly, I would not wish to be friends with someone like that. If she is doing that to her best friend, what does that say about the friend? As far as the best friend, she must have self-esteem issues. If I was friends with the best friend, I would talk to her about it. If not, I would just wish her well and deal with my friend (the one who is abusive). Again, if my friend was that sort of person and would not change her behaviour, I would not wish to associate with her. I do not like bullies and users.

you should tell her best friend that your tired of her shit and you should say that you gf doesnt want to talk to her anymore

get her a self help book about Toxic Friends.

You can't choose your gf's friends. All you can do is support her, help her understand how special she is and let her know that you are concerned and saddened by the pain her "friend" seems to be causing her. You might encourage her to join a new club or activity that will expose her to new friends so she can find a way to let go of this seemingly unhealthy relationship.

Considerately explain to her that a "best" friend would lift her up....not bring her down. This "best friend" sounds like she's got some insecurities and issues of her own, and belittling someone else somehow makes her feel empowered. Sad.

i would just keep your girlfriend away from this girl, keep her occupied. you won't be able to keep her away by telling her about your observation. she'll probably make excuses for her like we all do in some time or another... seriously, who needs enemies with friends like those

Be there for her, and remind her that "best friends" don't try to bring the other down. I wouldn't be surprised if your girlfriend was this other girl's only friend, and that's why your girlfriend continues to be friends with her. But that's something the other girl might have to realize if your girlfriend stops being friends with her. You're a great guy for being concerned with this.