不分彼此 [bù fēn bǐ cǐ]
1 形容关系很密切。
英 all is common; be on very intimate terms; with no distinction between what is one's own and what is another's;
1 比喻感情非常亲密。
2 同心合力。
英语 to make no distinction between what's one's own and what's another's (idiom), to share everything, to be on very intimate terms