Draco smiled, closed his eyes, and took a deep breath before casting what was after all not so much a complex spell as a complex string of spells that worked together.

She'd feel a warm and almost tangible band of energy appear round her throat, her waist, each wrist, each ankle, her biceps, and her thighs, and energy covering her mound, her lips, and her breasts and nipples - and she'd know she was hypersensitive under each of them.

He slid the fingers of his left hand into her mouth, which opened at the touch and made her lips tingle. "I could use this spell to turn you into a sex-slave, Hermione." His tone was dark and lust-laced. "Those bands will numb your hands if you so much as touch a wand, and if I press them against anything they will stick. You can't cum, and can't even prevent me putting whatever I like in your mouth or sealing your lips together."

His eyes were a lot less certain than his tone, slightly worried he'd gone too far, and he slid his fingers out of her mouth to let her talk. Almost needing reassurance that he was doing the right thing and he'd read her properly.