There is a saying that "indifference is half death"

To deal with this kind of people, using extreme methods will only make them find it interesting and make them continue. But it is also You can't soften your attitude, as this will make him think that this may be successful.

So I think the best way is to stick to the original attitude, not take any action, and show that he cannot affect you. Sister, stay indifferent, how long can he act alone? Right.

Hope it helps you.