Vice hides under a cloak of virtue.
More French Proverbs:
Those who shine in the second rank, are eclipsed by the first.French
Well fed but ill taught.
French
People count the faults of those who keep them waiting.
French
What a monk thinks he dares to do.
French
The early man never borrows from the late man.
French
A good bottle of wine does not need a cork.
French