Yeonjun was the crown prince and in order to become the king and for the kingdom to be in peace he had to marry you, the princess of another kingdom and have an heir, but you both hated each other, he treated you badly and was rude to you

Today was your engagement party but both of you looked as if you were on the worst day of your lives

It can't be I’m being forced to marry a spoiled brat like you he said to you annoyed