纸包不住火

纸包不住火:

Literally means:

fire cannot be wrapped in paper

Actually means:

Paper cannot be used to wrap fire because it will get burned. This phrase figuratively means that the truth will never be concealed and is soon out. Usually used to refer to something bad so the doer wants to conceal it from being known by others.

用纸来包火，反而被火烧掉。比喻事情的真相是无法掩盖的，很快就会暴露出来。用于不好的事情，多指当事人不想让别人知道。