a skeleton in the cupboard

skeleton in the/(one's) cupboard

An embarrassing or shameful secret. Primarily heard in UK, Australia. If you've got a skeleton in the cupboard, it will probably be exposed during this campaign. He didn't believe me when I said that I didn't have any skeletons in my cupboard.
See also: cupboard, skeleton
Farlex Dictionary of Idioms. © 2015 Farlex, Inc, all rights reserved.

a skeleton in the cupboard

a discreditable or embarrassing fact that someone wishes to keep secret.
A US variant of this expression is a skeleton in the closet .
See also: cupboard, skeleton
Farlex Partner Idioms Dictionary © Farlex 2017

a skeleton in the ˈcupboard/ˈcloset

something shocking, embarrassing, etc. that has happened to you or your family in the past that you want to keep secret: The new presidential candidate is certainly popular, but does he have any skeletons in the closet?
Farlex Partner Idioms Dictionary © Farlex 2017
See also:
References in periodicals archive ?
Jackie Grant Most people with a skeleton in the cupboard like to keep them there.
In second place was Andrew Laurence with his joke: "Most of us have a skeleton in the cupboard. David Beckham takes his out in public."
And yesterday Judge Thomas Fitzpatrick suggested the authorities have "a skeleton in the cupboard" after an expert witness was blocked from attending Donegal District Court by the Director of Public Prosecutions.