Here's an example of telling someone the truth, even though it hurts their feelings.

On 'American Idol' Simon is the most critical of the judges. He's blunt, sometimes maybe over the line; but who's critique do the participants value most? Simon can have even the men in tears, but because he is brutally honest everyone knows that when he gives a compliment that it has great value.
In real life we aren't as callous as Simon is on TV, but the principle is the same.