I (21F) still live with my parents (47F and 40M) due to high rent prices and terrible luck in the job market. Living with them also means living with my brother (15M).

For some background, my brother and I don't get along well but I stay civil and ignore him unless he threatens me or my dog which is fairly often. And my brother has punched me in the face before which led me to lose consciousness for a moment.

About a month or so ago, my brother got a knife (switchblade I think. Legal where I live). Ever since he's gotten that knife, he has continuously threatened to hurt me, stab me, cut me, and even made stabbing motions at me with it. It got to the point where I couldn't sleep and any sounds that sounded like that clicking noise they make would cause me to have a panic attack. My brother has formed several triggers for me like someone whistling a tune, snapping, the clicking sound, and seeing someone with a mullet to name a few.

So one day when he was at school, I hid it. He hasn't found it and I'm debating on throwing it away.

WIBTA if I threw my brother's knife away without him knowing?