A very important point to remember is never engage in name calling whether you are alone or in front of others. You are only going to make them angry and the point at hand will never get resolved. When you resort to name calling, the argument then becomes about the name calling and it is very degrading to another person to be called names. If your partner engages in name calling, walk away from the argument even if it means you have to take a walk or go somewhere to allow a cooling down period. Let your partner know, you refuse to engage in the conversation until they are ready to sit down and discuss the problem productively and name calling is not how to accomplish an adult conversation. You are an adult and should never use name calling as a way to seek revenge on your partner or to purposely hurt your partner's feelings.
Have you ever heard the expression "Tit for tat? Tit for tat is an English saying meaning equivalent retaliation.
This tactic may be appropriate for game playing or in a war, but it is definitely not appropriate in the game of love, it will only destroy your relationship.
Now to summarize being courteous. Never say anything to your mate, you wouldn't want someone to say to you, put yourself in your partner's shoes, think before you speak, never discuss a problem while you are angry,. never engage in name calling, and never resort to "tit for tat" tactics during a discussion.
Now on to the letter "D".