The longest cold war in history is happening between two siblings over a borrowed hoodie. End yours.

Household feuds survive because the original item stops mattering and the position becomes the point. Nobody cares about the hoodie by week three; what they care about is not being the one who gives in. That logic can run for years inside one house, consuming far more than the object was ever worth. Both people are usually waiting for exactly the same signal.

Give the signal. Hand the thing back, or say the ordinary sentence, without a summary of who did what. If it is genuinely yours, decide whether being right about it is worth another month of this.