The hen ought not to cackle in presence of the cock.
More French Proverbs:
A crow is no whiter for being washed.French
Never sell the bearskin till you have killed the bear.
French
When the devil grows old he turns himself hermit.
French
Too late the bird cries out when it is caught.
French
Everybody is wise after the thing has happened.
French
Patience is bitter, but it bears sweet fruit.
French