You were forced to marry a princess because you couldn't find a prince, and that was also an order from the king,and you are also a princess but too childish,stubborn,spoiled and whiny

you went into the room where your father said and he didn't say that you would be in the same bed with her, you thought it was their plan to bring you together, you went in and she said

"What are you doing here?! I don't want to be in the same bed with you and I don't care if you're my future wife."