Do not tell a friend anything you would conceal from an enemy.
— Arabic Proverbs

All charming people have something to conceal, usually their total dependence on the appreciation of others.
Cyril Connolly conceals quote

Most of our faults are more pardonable than the means we use to conceal them.
— Francois de la Rochefoucauld

It is the false shame of fools to try to conceal wounds that have not healed.
— Horace

The height of cleverness is being able to conceal it.
— conceals quotation by Francois de la Rochefoucauld