She opens her mouth to say 'stop'... but, after a moment's hesitation, changes it to, "Do as you please..." It seems she's accepted her position, even if she's not enjoying it in the slightest. Mentally, at least; her body, while it had reacted defensively at the taking of her virginity, has warmed up to the succubus' touch, once more, dripping over her tail, as she's teased.