Procrastination
There was nothing King Gwangjong wanted more than to laze about in his bed all day-one of the few where he didn't have to deal with obnoxious chatterboxes who thought they could play him like puppets with their fragile strings. He deserved it. But, then, Hae Soo glanced at him from the corner of her eye and airily said that if he's content with his physical activity consisting only of sitting all day long on the throne and in his bed, he'd be out of shape in no time.
"Don't come complaining to me when you're thirty and already have a pot-belly~" she sang and waltzed out of the room, but not before she stuck out her tongue at him.
The king decided he didn't see his adjutant's shoulders tremble with suppressed laughter.
When His Majesty King Gwangjong ordered him to schedule training exercises with the newly appointed general for most of his off days, His Majesty's loyal adjutant decided wisely to remain silent and obey.
Few people approved of Lady Hae Soo's existence and influence over the king like he did.
A.N:
I look at the king's secretary/adjutant/whatever during the first days of So's reign and thought: With the way So is interacting with Soo, I bet it's an entertaining show for whichever babysitter's doting on the king to watch. Also submitted at Archive of Our Own.