1. be unpleasantly self-assertive, get angry
he/she was throwing their weight around
The idiom to throw your weight around means to behave as if you have a lot of power or to use your position unfairly or aggressively in order to get what you want. You can 'throw your weight around' physically by intimidating others or you can 'throw your weight around' by reminding others of your power or position in a threatening way. This is an informal expression used more often in casual contexts.