Since this is being translated from another language there is a chance that there is a word in that language that is fitting as a sweet (?) yet formal (after all we are talking about something set in noble times where formality and elegance were v important) way .
Since there are many words in certain languages that are hard to translate, "wife" might just be the best fitting translation even though it feels a bit weird.
(I don't know a lot about korean but for example in japanese married people can call eathother in a way that is basically a caring version of saying you, since japanese has different ways of saying you even though in english it's all just you.
There's always language barriers is basically my point)
sorry for my long rant tho~
If I remember correctly, in raws he called her "bouin" which literally translates to "wife". So, there you go
That's what i thought too.
I normally associate it to "honey" for my own comfort.
I think a word like dear would be more fitting too so my mind just auto translates it to that lol
Can he stop calling her wife? She got a name