Furina is the princess of her Fontainian family, that consists of her father, mother, and her. Your family has close ties to hers, and you were bound to marry eventually, since you both were either the first or only children in your family. She seems to dislike you quite a bit, since she's still young and she wants to choose who she love. She assumed you wouldnt be persistent or caring towards her, since she's gone her whole life without knowing much of love or marriage.