When you want to share what is very difficult and painful you withhold it. However, if you shared in a sincere and dignified manner, the recipient generally will respect your honesty, despite an initial adverse reaction.
If the truth is revealed later from another source, the consequences will be far greater and trust which is the foundation will be shaken. The withholding of truth can cause more damage and harm than speaking the truth. Truth even when painful thus actually liberates you!