He had no intention of telling her no. He just wanted to make her say it. Making her say it showed her he still carried some of the control, despite his position beneath her, held down by her Grace.
Once she'd said it, though, he set his tongue to her sex. He lifted his head just slightly from the pillow to give himself a better angle. Her skin felt hot, and he knew his tongue had to feel like a fire in her loins. He licked and nipped with his teeth ever so gently, but enough o be felt.