Their relationship is special.
They are not a couple, nor are they friends.
They would sleep in the same bed without a problem, and they would hold hands when traveling.
He would also put his arm around her shoulders. She would also hold his arm.
He would cover her hands in winter, and she would wipe his sweat in summer.
He would bake cakes for her while working overtime, and she would make him coffee during night battles.
He would give her bath water and she would bring him a change of clothes.
He would buy her painkillers while she was having sex, and she would give him massages when he was tired.
Forgot to mention, they are work partners, or work partners. In short, they are not subordinates or superiors.
He also forgot to mention that she would go out to get drunk on the night of his one-night stand, and he would show up when she was drunk, carry her back to the hotel, and make her breakfast - a sobering meal.