Dear LFTP: should I tell my siblings about my mother's affair?

• Should I tell my siblings about my mother's affair, which could change how they view our father?
• Do you have a responsibility to come to the defense of people being maligned by things you know to be untrue?

A listener writes that at a funeral, her aunt confided her mother cheated on her father while they were married — the father apparently unaware. Her mother's lies during an ugly divorce (other children, pedophilia, hidden millions) made her siblings idolize the mother and loathe the father, and the listener wants to know if revealing the affair could change their minds. The hosts say they don't hide true things and that lies should be answered with truth, but the motivation matters: first give the mother a chance to come clean with an ultimatum, don't weaponize the information, and be 'triple careful and prayerful' since you may personally benefit from spreading it. One host notes revealing the affair doesn't technically disprove the other accusations, but it exposes the mother's credibility. The Secular answer asks why the aunt shared it, names the behavior parental alienation, and says to disclose only if 100% certain the claim is true.