To what extent is it true that obscenity is a relative concept, and that some vulgar words are considered normal and common in certain regions, even if uttered by a son to his father?

Foul language is among the things Allah dislikes, as Allah Almighty says: ﴿Allah does not like the public utterance of evil, except by one who has been wronged.﴾ It refers to ugly words and deeds that are disliked by nature, and expressing repulsive matters with explicit terms. Foul expressions are used in cursing and shaming. Obscenity varies according to customs; what is condemned by people of dignity is considered part of the forbidden obscenity. One must choose words appropriate for parents and their status, and for this reason, scholars have prohibited a child from calling their father or mother by their names, due to the disrespect it entails.