Responses
yes, its a cultural thing. and we rarely uses our partner names. idk how to explain, but usually we use pet names??? like my sis called her husband honey or darling or "dad," (not in sexual way, it just the way it translated to english). my parents sometimes use full names to address each other instead of given name. it gives some kind of respect to your spouse/partner
so yeah, i get why you said mind boggling because it kinda weird to me too when i saw westerners called each other first names instead of using honorific when they aren't like close or familiar with one another.
I know it’s likely a cultural thing, but it’s mind boggling to me how they live together, have sex, promise to spend their life together, and yet call each other by their last names/use “san” or “sensei”