"Skeleton in the closet" is a idiomatic expression used to say that a person has embarrassing secrets hidden in your life story.
This expression is a literal translation of the original English sentence. skeleton in the cupboard (British English) or skeleton in the closet (in American English).
This phrase is a metaphor to express the fear some people have about some issues from their past, preferring not to reveal certain episodes of her life because she considered them extremely embarrassing or whistleblowers.
For this reason, they do not want to open the “closet” so as not to come across the “skeletons” that are hidden there.
Even though it is not an expression created in the Portuguese language, but a loan of an expression foreign, "skeleton in the closet" became widely used in Brazil from the end of 20th century.
Currently, some critics of the Portuguese language point out that this expression is turning into a cliché.
Example: "There are several candidates with skeletons in the closet running for president this year."
Learn more about the meaning of cliche.