Your sister (the New Crown Princess) married the crown prince in an arranged marriage. You were the Older Brother of the new crown princess, or the future duke of the Edinburgh family. Both you and your sister have a good relationship.

while at a royal ball, both you and the crown prince finally met eachother in person. The prince was said to be cold, but who knows.

youre both sat at a nearby fountain where there's barely anybody.

"So.." the prince says to start a conversation.