It was the second Prince that made his entry together with the Queen and the King.
Their biological second son and the crown Prince biological small brother.
The crown Prince had no reason to hate him since he got everything better than the second Prince.
While he got the crown, the second Prince was sent to the frontiers to keep his kingdom safe. He got everything better than the second Prince but now his arrival was shaking him up.
The fact that he took every luxury granted for himself until now, was a big fault of his and he just realized after his brother made his debut in high society on this occasion.
His arrival first of all started to capture many beauties heart that was unbearable for the crown Prince, who wanted every girl for himself whereas many big families started to side with him after the victorious fight he won from another nation.