I would like to know what "mind our own business" means in the following sentences:
‘There’s no law against what we’re doing.’
‘I know that.’ Your voice softened. ‘But we need to act as if there were. Do you know what they did to Foucault?’
I looked at you blankly. ‘The philosopher?’ You nodded. ‘What’s he got to do with us?’
You sat up on the bed, your back against the wall. ‘He came to Warszawa when he was young to head some French cultural institute, and the Secret Service knew about him. So they found a handsome student and introduced him into Foucault’s circle and made sure the guy charmed him. It worked. One day the two of them took a room at the Bristol and boom’ – you snapped your fingers – ‘in come the agents, catching them in bed. They charged Foucault with soliciting prostitution. A week later he’d resigned and was back in Paris.’ Your voice sounded almost triumphant, as if impressed by their efficiency. But for an instant I saw a wavelet of anxiety ripple across your face. ‘You see?’
I said nothing. The water pipes churned with a low thud, and I felt a heaviness settle over me.
‘And you want to live like that, Janusz, in fear?’
You laughed, your confidence in place again. ‘I’m not afraid. We just need to mind our own business. Avoid risks, be smart. As long as we do that, we’ll be fine. Don’t you think?’
I shrugged, feeling defeated.
In this novel which is set in the 1980's in Poland under the socialist regime, where homosexuality was socially unacceptable, the protagonist Ludwik (a university graduate) left Poland in 1981 to live in the United States of America. And he remembers what it was like back then in Poland, where he went to the flat of his lover Janusz, who was recently hired as a worker for the Office of Censorship. At Ludwik's question asking whether he should pick Janusz up after his work was over tomorrow, because tomorrow was Janusz's first day at work, Janusz said no, it would be better not to give his co-workers a reason to be suspicious. Ludwik darkened, wondering whether their relationship has suddenly become a secret, but Janusz explained that they must be careful because the authorities might use information when they learned that they were homosexuals, taking an example of Foucault.
In this part, I wonder what Janusz had meant by saying that they had to mind their own businesses. I've often heard people saying "Oh, mind your own business!" in an irritated way, but I think this business-minding may have another connotation, another meaning, so I wanted to ask you.
I am an English learner from South Korea, so thank you for your patience in advance as I may not know obvious things. I would very much appreciate your help. :)