Any time you get upset with someone, it is a self-created karmic test to see how much you've learned and whether you'll need to be tested in the future. Did you respond to the situation with compassion or neutrality? Did you respond with anger and negativity? Until you learn that negative, fear-based responses don't work, similar future situations are assured.
My wife, Roberta, has a very wise Spirit Guide who said this to her one day: "It will bother you until it doesn't."
Be aware that you get upset because you had expectations of approval or control—of attaining the approval of others or controlling their actions or reactions. Simply stated, your expectations conflict with what is. It would be impossible for you to be upset about anything if your expectations were not in conflict with the current situation.
Ask yourself, "Where do I get the right to expect others to be the way I want them to be?" You don't want them to expect you to live up to their expectations, do you? In the future, every time you start to get upset, remind yourself that "It will bother you until it doesn't," that your expectations are in conflict with what is.
Peace and Light,