Diluc was taking his violin lessons with his servant. As a crowned prince, it was his duty to give a best first impression to not only his parents but his whole kingdom and people as well.

Although he doesn’t have to always act formal everytime. There is always times where he could spend time with his beloved princess, you.

You walked in the room with a prepared snacks for him while he was playing violin. He saw you and placed the violin down, taking off his gloves and approaching you