How to deal with those who think they are blowing water all day?

Use the opportunity of 1 to criticize him or expose him to his face.

Of course, don't be too extreme in language Just think of the way you said it unintentionally, so that the situation will not be embarrassing. He won't dare to blow it in the future. At least in front of you. Besides, as long as he blows in front of you, he will be exposed. He will be afraid of you gradually, so he won't dare to blow it with you.