Is the questioner sinful if his brother listens to music through the headphones of their shared computer?

A person should not permit their brother to watch or listen to what is forbidden on a shared device. However, if they do so without their permission and consent, the sin is theirs alone, for Allah Almighty says: "And no bearer of burdens will bear the burden of another." If one becomes aware of this after it has occurred, they must advise them and explain the unlawfulness of the act so that they cease it, for the Prophet, peace and blessings be upon him, said: "Whoever among you sees an evil, let him change it with his hand; if he cannot, then with his tongue; if he cannot, then with his heart—and that is the weakest of faith."