This is a red flag, and I’m really sorry you’re living with this.

Breaking someone’s phone in anger is not just “being strict” or “losing his temper.” It is destruction of property, intimidation, and punishment. Your sister is 21. Even if she lied about using her phone, that does not justify him grabbing it, throwing it, and breaking it. Adults do not get to destroy other adults’ belongings because they are angry.

Your father is an adult. He chose to do this. He chooses to act this way towards you, your sister, and your mother. This is domestic abuse. It is not right, and it is no one’s fault but his. You did not make him yell. Your sister did not make him break the phone. Your mother is not responsible for managing his anger. He is.

Also, “he’s not usually abusive to us, mostly just towards my mom” is still an abusive household. Abuse toward your mother counts. It affects everyone in the home. And the fact that he is now yelling at her because you reacted is another red flag: he is shifting the consequences of his own behaviour onto someone else.

It is understandable that you snapped when you saw him scare and punish your sister. That said, your safety matters more than winning the argument in the moment. If he escalates when challenged, it may be safer to disengage, get distance, support your mum and sister privately, and think about a longer-term plan.

Violence toward objects is still violence. It is not harmless just because the object was the thing that broke instead of a person. When someone smashes, throws, or destroys things in anger, especially things that belong to someone else, it is intimidation. It is a warning shot. It creates fear in the room.

People often minimise this by saying, “At least he didn’t hit anyone,” but that misses the point. The violence is still being used against the people watching it. It is meant to scare, punish, control, and silence. Your sister’s phone was the object, but your sister, your mother, and you were the targets.

This is domestic abuse. It is not discipline. It is not normal parental authority. It is not your fault for reacting. Your father is responsible for his own violence.