闺蜜抢走了我的男友
[guī mì qiăng zŏu le wŏ de nán yŏu]
This translates as 'My best girl friend stole my boyfriend.' It conveys the sadness or resentment from a betrayal scenario where someone very close, like your closest female friend (bestie), takes away something precious to you – here it's specifically referring to one's partner.