Humans are designed to naturally avoid confrontation. Some of this is a good thing. We do not touch the stove as children because it will burn us. But sometimes we are confronted and it is needed. Without confrontation we would never try anything new, or move out of our parents house, or be in relationships.
We all have our automatic ways of dealing with being confronted. Some people get sad and shut off. Others push back by attacking, pushing the attention away from themselves. Others just walk away and avoid any possible benefit. Whatever the case may be, we all have some automatic response, we are programmed with it as humans.
When you are in relationship with anybody, one of the greatest things you can do is recognize this response when you see it. You are not dealing with the actual essence of the person at this time, you are dealing with their "stuff," their automatic way of being. One of the greatest gifts you can give anybody is to look past this and stand for them anyway. Even though they may want to quit, or attack back, or be sad, acknowledge that greatness is still there and this is just a time of automatic response. It is not easy to do this, but it is a wonderful gift.
Stand for greatness, not stuff. Be the gift.