He is like a silver pin, Fair without, but foul within.
More French Proverbs:
A person is unlucky who falls on his back and breaks his nose.French
He has eaten his corn in the blade.
French
War makes robbers, and peace hangs them.
French
When he was fifteen the devil was a good looking boy.
French
If your head is made of butter, don't be a baker.
French
Old love and old brands kindle at all seasons.
French