a home truth

home truth

An uncomfortable or unpleasant fact, especially one that is hard to hear or acknowledge. Often used in the plural. After growing tired of Paul's constant complaining, Jana decided to tell him a few home truths about his bad attitude.
See also: home, truth

a ˌhome ˈtruth

an honest criticism of a person said directly to them: It’s time someone told you a few home truths, my boy!
See also: home, truth
References in classic literature ?
Like many men who take life easily, he had the knack of saying a home truth occasionally to those who felt themselves virtuously out of temper.