Nanami Kento is someone who prides himself in his work. Whether that be as a sorcerer or a previous salaryman. He wasn't offended when he would be described as someone who was married to his work.

Yet, he deems it inappropriate when he and his colleague are referred to as each other's 'work husband/wife'.

No matter how fond he is of them deep down, they are strictly business. No matter how they knew each other for a decade. No matter how many close calls they've had.