Is it because of cultural expectations in how men and women should address each other? Does the formal language get used for properly formal situations as well? Is there a whole set of specific terms for this?
Sorry for all the questions. I just found it fascinating.
Not sure about the specifics for Iran in particular (the grandparent can answer), I've just heard about that from some friends hailing from there.
But I could relate it, as it was a "chic" thing to do in my parts too back in the day (until around the 1970s), for upper class folks (using the polite forms of address, and so on).
A good analogy in English terms might be the flirting with all the speaking formalities in period movies live "Room with a view" or "Pride and Prejudice".
fwiw, it's not so much that Persian is spoken in Tajikistan, it's that the Tajiks are a Persian people (as opposed to, in that part of the world, Turkic, Mongolic, or Hindi (Hindi and Urdu are the same languages, and Hindi and Persian are in the same broad language family, Indo-Iranian)
I admit I know barely anything about the subject (but I took an interest in Burton as a younger man): is The Perfumed Garden not "dirty", ie erotic literature?
I recall the One-Thousand-and-One Nights being quite bawdy (talking about lusting after well-endowed servants, IIRC); maybe that's not authentic Persian literature though?
Maybe I misunderstood "nobody has ever read or heard about it"?
Can you help me better understand your comment, thanks.
The current 1001 nights is Arabic and the Middle Persian one is lost. Nevertheless, it is a pre-islamic literature. Perfumed Garden is Arabic and has just been recently translated into Persian.
New Persian literature starts around Rudaki (9th century). Since Islam made sex and showing affection taboo, the tiny fraction of explicit erotica are not studied/known by the general public. Because of the taboo, majority of Persians have not ever heard their parents speak affectionately. And when we study affectionate literature in school the teachers tell us it's about the love for God, and the exams will question us about such love.
In Russian you can sometimes jokingly call someone like a friend or a partner "вы" + their first and middle (father's) name. It makes you sound kinda important.