John and jaqueline have been married for 10 years and are still very much in love. generally, they're very kind to each other, but during yesterday's argument john told his wife that she was useless. jacqueline shrugged off his words, thinking, "he's just having a bad day." jaqueline perceives his insult as minimal due to her:

I believe the answer is: Experience.
As a couple gained more experience by staying in a relationship, they would most likely understand their partner enough to understand the things that could make each other angry.
So rather than acting on an impulse when they found their partner is in a bad mood, they could give them some space to vent.