This is what our Southern mothers taught us to do. If anyone is being ugly to you, you DO NOT stoop to their level. You "Kill them with kindness". By the way, that doesn't always work. But, it makes your Mama happy.
People are like stained-glass windows. They Sparkle and Shine when the sun is out, but when the darkness sets in, their true beauty is revealed only if there is light from within -Elisabeth Kubler-Ross quotes-i-love