Truth indeed rather alleviates than hurts, and will always bear up against falsehood, as oil does above water.

Being told the truth hurts less over time than being handled. A hard fact gives you something solid to stand on, while a kind evasion leaves you working from a map that does not match the ground. The pain of honesty is sharp and finite, and the damage of a comfortable lie compounds.

When deciding whether to say something difficult, imagine the version where they find out later and realise you knew. Then say it as plainly and as kindly as you can manage at once. Most people prefer accurate information to protection they never asked for.