The Kural in life
If they betray intimates, they'll spare no one.
Valluvar offers a test of trustworthiness. If broadcasting even a close friend's faults is someone's habit, what cruelty will they spare a mere stranger? One who exposes the people nearest to them has shown they can be trusted by no one — the very closeness that should protect a confidence becomes, for them, just more material.
Parimelazhagar: nothing is crueller than broadcasting.
Parimelazhagar weighs the word 'tūṟṟudal' — to broadcast, to spread for all to know — and finds nothing crueller; that is why the verse cries 'what then will they do to strangers!' The argument is from the greater to the lesser: if even the protection of intimacy does not stop a person's tongue, no lesser bond possibly could.
Whom you can never confide in.
There is a practical filter in this verse. Watch how a person speaks of their closest friends and family when those people are absent; that is exactly how they will one day speak of you. Someone who treats intimacy as no barrier to exposure has told you, in advance, that no confidence you give them is safe. The cruelty isn't reserved for enemies — closeness simply provides them better ammunition.
One who broadcasts an intimate's faults will spare no stranger.
Valluvar offers a trust-test: if broadcasting even a close friend's faults is someone's habit, what cruelty will they spare a stranger? Parimelazhagar: nothing is crueller than broadcasting, so if even the protection of intimacy can't stop their tongue, no lesser bond will. The closeness that should guard a confidence becomes, for them, just more material.
Judge whom to confide in by how they speak of their closest people.
Use this as a filter: watch how someone speaks of their closest friends and family when those people are absent — that's exactly how they'll one day speak of you. Someone who treats intimacy as no barrier to exposure has told you, in advance, that no confidence you give them is safe. Don't hand your secrets to a person who broadcasts their intimates'.