How should children deal with their father who confessed to adultery: as a father or as an adulterer?

It is obligatory to be dutiful and benevolent to one's parents, even if they are disbelievers. Their right does not fall due to their disbelief. It is appropriate to advise a father who openly commits adultery by explaining its gravity and the warning associated with it, while also drawing attention to the danger of openly committing sins.