Tell your partner if something they did upset you, and listen to them when they do the same.
Relationship advice: Don't let it fester
The little things matter - whether good or bad. So if you don't like something about your partner, talk it out instead of sulking silently. What may have started out as a small irritation is often blown out of proportion because we let things fester. When you get into the habit of being frank and upfront with each other, a lot of trust is built in your relationship. Moreover, once you get it out of your system by saying it out loud to your partner, you may realize that what had been bothering you really was just a trivial matter after all.