mind your own business

Từ điển Oxford Advanced Learner 8th

ˌmind your ˌown ˈbusiness idiom
(informal)to think about your own affairs and not ask questions about or try to get involved in other people's lives
•‘What are you reading?’ ‘Mind your own business!’
•I was just sitting there, minding my own business, when a man started shouting at me.
Main entry: ↑mind_idiom