Often, the information that we don’t want to hear is THE most important. We may want to hear that information, and be most grateful to those who do not take the easy way out. But that doesn’t mean it will be easy, or that we will always be graceful.
When we give feedback, it is important to remember this. You are (in the right instance) doing a favor, and the right thing. If the other person struggles to hear it, try not to take it personally. After some time, they may thank you immensely, whether out load or just internally.