男朋女友
[nán péng nǚ yŏu]
This phrase mixes traditional gender-specific terms for friends - 男朋友 (boyfriend) 女朋友(girlfriend) together to create a unique concept of 'female-boyfriend/male-girlfriend'. Usually it refers to platonic friendships that cross gender lines but also carries a nuance similar to 'girl-crushes/boy-crushes'.