Shall we set some ground rules?
Try to phrase criticisms constructively, or preface them with positive statements.
Example: "Kate, I love how you are so open-minded. However, I have to take issue with your statement regarding legalizing the shooting of house cats in the suburbs."
Use "I statements" whenever possible.
Example: "Dad, I feel very angry when you criticize Michelle Obama's wardrobe choices."
Just a start...