Honesty is a great virtue, but silence can be priceless.

Years ago my college room-mate got involved with a real loser. Most of her friends and both her sisters repeatedly and honestly told her that he was trouble and that she would be a fool to marry him. Result -- she married him, out of sheer stubbornness, and because she was too embarrassed and harrassed to admit they were right! If more of her friends had provided non-judgemental love and support(which I felt was the only sane response to the situation, though I often cried about it when we were apart) rather than "honesty", she would have come to her senses. The marriage lasted less than three years. On the other hand, our friendship has lasted over thirty years, and she and I were both holding my father's hands when he breathed his last.

A friend accepts you for who you are, what you are, and as you are -- and is there for you through the good times and the bad -- and it's a two-way thing.