A light novel romance of danger and desire?

Noblewoman Giselle's world is turned upside down when she's summoned to serve as the king's prized concubine. Her heart already belongs to her manservant, Wallace, a soldier who worships the ground she walks on. Just as Giselle accepts that their blissful days are numbered, Wallace steals into her room in the palace with a desperate, hungry gaze. Spending the night with him is tantamount to treason...but their love is not one so easily denied.