Guard your heart. Anger has a way of spilling and amplifying your private thoughts to an audience of one or more who may never forget what you said no matter how many times you apologize. They can forgive you but your ill spoken words may still burn. Clean your heart. It keeps you from sinning while angry. That way if your heart spills in anger, at least you are being painfully truthful. Still ask for forgiveness when you realize that you hurt them then ask the Lord to help them see why you said what was said. At times, truth has to be forced out.