Rodolphus suspected she wasn't going to be doing that again in a hurry. Perhaps her incarceration had made her learn her lesson. But it didn't mean that he would ever submit to her completely, nor would he let her ruin all the progress he had achieved behind the scenes.
Dark eyes and bloodied lips were enough to arouse his desire, but to see her fight and struggle against her bonds was truly something he was enjoying. For just a moment, he toyed with the idea of bringing out his whip, knowing just how much they both enjoyed that. But the potions she was taking were possibly fuelling this mood of hers, and that was good enough for him.
Her robes had fallen away, yet he made no move to release her from her bonds. When she hooked her leg around him, he nearly stumbled as he was pulled in close. He snickered at her growl, even as he began to calmly unbutton his own robes. He could leave her there, unbound, or he could let her go free, and see just how she wanted to play this little game. They both knew what the outcome was going to be, and as he flicked his wand to release her bonds, his teeth bit down on her shoulder as he was intent on marking her.