said no at any time, and often does
And then she returns because she does it for Griffindor and your character can provide some points. But your character also is a part of conspiracy with a goal of drawning her faculty so you could force Hermione into the slut life. And to achieve that you destroy her self-respect and her faith in herself, while posing as an ally of some sorts. She begins to rely on her looks and sexual favors not because she is interested in it, but because she doesn't think that her smarts and hard work will be enough and she is desperate. She is not Stockholm-Syndromed in a sense that your character doesn't threaten her with a gun or something like that, she never even sees you as a threat, but that doesn't detract from a fact that you are, indeed, a threat. Even more, your character is THE threat, evil mastermind behind her problems, her despair and her eventual downfall.
Listen, I get your point. I love stories where girl "discovers her inner sluttiness with proper encouragement" myself, but Witch Trainer isn't one of them. In fact, I think that it is one of the most rape-themed games ever created even though there isn't one scene of actual rape in the entire game. And I do love that in his Star Channel game Akabur walks away from this rapey dynamics, going for the themes we all could enjoy more.