The idea of hidden love is strange. Perhaps we think of secret love which a man or woman have for each other, which they do not yet feel ready to declare, for fear perhaps that it will not be requited.
Parents must be wiser than their children in looking beyond the present moment and being prepared to administer discipline in the interests of dealing with sin early in the life of the child. Even though the child may resent this in the short term, hopefully correction will bring them to a better frame of mind in which they will come to agree with the parent and even condemn their former rebellious attitude.
A deep friendship is something strong that can bear the strain of faithful and loving rebuke without being broken. But if a friend looks on while we do wrong and does nothing to correct us, there is little value in that friendship.