<human>: My girlfriend and I have a happy relationship and do most things with each other, neither of us are 'troublemakers' by any means, and we don't really like getting into any trouble, going to parties or drinking/getting high. We just kind of avoid it..

While my girlfriend is with me, she claims she hates doing stuff like that, and doesn't want to get involved. But when shes with her best friend, they always end up doing something that she claims she wouldn't do, like getting drunk, etc... She immediately afterwards apologizes to me and claims she regrets it, and doesn't want to get into it again. She seems genuinely serious when she says this and I believe her when she says she honestly doesn't like it.

It seems every time I let her alone with this friend she has, she falls into peer pressure and just does things that she later regrets. She can't seem to break out of the loop.

I'm pretty lost on what to do or say to her. Any thoughts, opinions, comments, concerns advice? All is appreciated. Thanks

Could you distill the essence of the text into 1-3 sentences?
<bot>: GF falls into doing things she later regrets with her friend. I'm worried about her. Not sure what to say or do.