@Edixo Because a) She is the hottest girl and the author needs content with her, b) the authors of manga and LN for some reason are sure that any girl, regardless of her sexuality, dreams of harassing girls with an excellent body.
Poor Banchou the broom stuff was too much, good girl Banchou just wanted to be considerate and reassure here deer friend. Thou the begging was kinda hot, Fummi looks like such a carnivore and Banchou like a big helpless sheep, so sad it went too far