maimerart:

1. Yes, Russians use them a lot, but only in deeply established relationships.  
If Victor and Yuuri are not in an established relationship, Victor bombarding him with zolotse&solnyshko is a little strange and too extra even for him XD If you want to use those in a fic, make sure the situation is appropriate.

2. As long as they’re speaking English, I think Victor would in fact use English nicknames like ‘Love’ or ‘my dear Yuuri’ or something else that fits his characterisation in your fic! It’s hard to switch between languages quicky (“english-english-solnyshko-english-english”), because the pronounciation differs A LOT and your tongue is going to fail you if you’re not a genius of articulation. xD 

It’s not only the pronounciation that makes switching difficult, especially in the same sentence, but the process of thinking. When I start speaking in English, I also think in English, and when I think in English, no Russian words pop up in my head. Russian just disappears, and it takes an effort to switch back. It’s much easier to stick to one language in your speech. And there are enough sweet words in English which Victor could express his huge love with 🙂 So instead of “english-english-lyubimiy-english-english” he would 100% say “english-english-my love-english-english”.

3. If Victor decides to use a Russian word or a phrase, I don’t think it would be in vain. Quite the contrary, actually: it would be intimate, sacramental even, it would express something that English can’t convey for him.  He would make a pause and say it softly, slowly, right in Yuuri’s ear, so that Yuuri could understand it without knowing the translation and feel the vibes with his skin and heart, you know? I imagine English is an everyday means of communication for them used in all kinds of situations, but Russian or Japanese are only for special occasions to express very special emotions. You should avoid inserting these languages randomly in the dialogues.

It seems that these two words – zolotse and solnyshko – are the favorites of the English fandom. At least I have seen them more often than other Russian words on AO3. Zolotse means gold, and solnyshko means sun, both nouns contain suffixes of endearment  and sound cute (in Russian not only personal names, but also most nouns, adjectives and adverbs can have “cute” derivatives). Victor might use them, why not, if the author sees him using such words. But you’d almost never encounter those in Russian fics… I think Victor is less sweet in Russian fics in general. For some reason there are many fics exploring his “dark Russian side” and his flaws, and honestly it’s not my cup of tea xD But even in fluffy fics he doesn’t use such words much as compared to English fics. Here is a little list of what I have seen Russian authors using:
Moy Yuuri (my Yuuri) – мой Юри
Miliy (dear, sweet) – милый (may be used as an adj or noun)
Lyubimiy (beloved, my love) – любимый (may be used as an adj or noun)
Moya radost (my joy) – моя радость
Solnyshko (sun) – солнышко
Lapochka (cutie) – лапочка
The first three tender ways of addressing are the most neutral and fit all situations, but the last three may be too cheesy, banal even. Or may not. It depends on the situation and the context, on the talent of an author. In my own 78k Russian fic I used only “my Yuuri” and “miliy Yuuri”. 

These nicknames are very common in Russian, but it’s a very creative language and due to those endearment suffixes technically any noun or adjective you want can turn into a sweet nickname. I rather think Victor would use the creative ones, something unusual but meaningful!

Sometimes unexpected pet names are awesome if there is some explanation behind it. For example, in Blackbird Victor calls Yuuri moya iskorka (my sparklet), and it is so so so good in that story, so right! This is just genuis! Not cheesy or strange, but very romantic, 100% believable and full of meaning! I was extremely delighted to encounter that one!
But if you want something like that, you totally shouldn’t use Google Translate xD You need somebody to explain to you all connotations of the word you want to use. The vibes of this word in the Russian language.

I personally also like the word “rodnoy” – it is “dear” with a family feel to it. It sounds like “you’re my family” or “my soul mate”. Like “you’re in my blood/soul”. It’s more than just emotions, it’s some deeper connection that is beyond them. But it’s not an easy one to pull off in a text. This must be a serious text, then this word, whispered by Victor, would become pure magic ❤
And I also like “svet ochei moih” (the light of my eyes). This is an old Russian way to address a beloved man, very sublime, poetic, archaic, and MUCH harder to pull off. But it’s… beautiful…

TBC ❤