Being right does NOT authorize you to respond wrongly.
Your spouse may have forgotten something or done something annoying or flat-out not do something they had promised to do or not even care, but we are to:
be kind and gentle
...with our words and actions (see Ephesisans 4:29). I may be right about a matter, but I automatically go into the red zone of being wrong the moment I start nagging or raising my voice or criticizing or complaining or using ultimatums or thinking up "punishments" or use an irritating tone of voice or just glaring... Okay, as you can see, I can be childish, petty, and (oh-so) despicable. Simply, I am the one in the wrong. The examples are endless, so I won't bother giving one ;)
Oh, and I think this concept is definitely not restricted to marriage (spouses and parents tend to bring out the worst in you!) but can apply to any relationship of any sort.