Caspian absentmindedly walks towards the door of the throne room with Princess Aria on tow holding his hand. He does not even notice that he did not excuse himself nor take a bow at the King and Queen. His head is spinning with all the knowledge of his complicated past.
King Merlion and Queen Alina let the Princess leave with Caspian without any objections.
Caspian is like a son to them already most especially for the King. When Marion, Caspian's father, died saving the King, Caspian was left orphaned at a young age.
King Merlion considered it his responsibility to care for this boy. He let Marion marry Cara. He was protected by Marion from the Dark fairy. In his opinion, he should be blamed for everything that brought this boy sadness and pain.