亲兄弟明算账

亲兄弟明算帐

Literally means:

brothers need to figure out the money, too

Actually means:

accounts should be settled without ambiguity

Even brothers of the same parents should settle their accounts with no mistake.

It figuratively means no matter how closely two persons are related,and no matter how deep their relations are, they should settle their accounts fairly without ambiguity in accordance with the rules. It implies that neither side should take advantage of the other, or that they should not break the accepted practice and should avoid future conflicts.

即使是同一父母所生的兄弟，也要算清楚钱财方面的账。

比喻双方关系再好，再密切，也要把钱财算清楚，或按照规矩办事。含有彼此不占对方的便宜，或避免发生纠纷或破坏规矩的意味。