The way he hauled up her skirt and then summarily struck her bottom had her seething with indignance at his audacity. Somehow though, the way he held her hand, and the way she squeezed his tight in return as he beat her, signalled not just her consent to this violence but emphasised that it was the height of eroticism for him to control and manhandle her in this way.
That's why, when he barked, "have you forgotten your manners?" as he punished her, she didn't hesitate to reply, "No, thank you Sir", as she experienced a burning desire to rub her clit furiously as he thrashed her.