All truths are not to be told.
This proverb means that sometimes it is better not to reveal the truth, especially if it may hurt someone’s feelings or cause harm. It implies that discretion is the better part of valor.
Is there a truth which must never be spoken?
Yes, a man should never say what he really think of your wife, if that thing is not flattering. If you do, your universe could quickly become cluttered with unidentified flying objects.
That is not to say you lie to your wife. You never do that. But if you must say something, do so respectfully giving room for her self esteem.
Nothing is more fragile than a person’s self esteem and few things can do more damage quicker than a thoughtless comment.
Women, the same thing goes the other way as well. Men’s self esteem is just as fragile but men are far more obtuse when it comes to emotions. Men need wiggle room to climb back on their delusional pedestal just as women need their emotional landscape to be fortified with self-assurance in what is for them a far more dangerous world than men can generally even think about never mind understand.
You can be brutally honest (your version) or be honestly giving and supportive. One road leads to mental hell and self replicating anguish and the other leads to mental and emotional health, wealth and stability.