If you allow your mental state to be dictated by other people's behaviour, you are their slave
Emotional reactivity is the ego's way to project it's own pain unto other people. If you think that another person is the source to your anger or misery, you will remain lost. Another person might trigger that emotion within you, but they are not the source of that emotion, nor are they responsible for thos emotions. You are. Every emotion you feel is already there within you. A trigger only points to an unconscious emotion or behavior in you. If you allow yourself to feel it and own it yourself, it has something to teach you.