Disclaimer: I do not own Harry Potter.

In the dark of the night, she watched him sleeping next to her. His dark hair was messy from hours of lovemaking, the sheets strewn carelessly around his waist. Her brown eyes were transfixed on the rise and fall of his chest, where a light dusting of hair trailed down to his stomach and disappeared under the blanket.

She shifted slightly, not enough to wake him, but enough for him to stir. His arm that was wrapped around her waist tightened fractionally, and from between his full, red lips, a breath of hot air that she knew tasted of ruin and heaven and sin rushed out. Her fingers reached for him, and traced swirling patterns on his body. Under her touch, she thought he felt like fire to her. Fire and sparks and smoke. Something about him made the blood in her veins burn, made her feel as though a flame was simmering just underneath her skin.

Vaguely, she wondered if he felt the same way. She remembered the intensity in his gaze, the worship his hands whispered of. She gave an involuntary shiver.

Lifting her leg, she was straddling him in one swift motion. His breathing stayed steady, and there wasn't so much as a twitch to tell her that he was awake. But in her gut, she knew he woke then. Perhaps even before. He was a great actor, after all. One of the best liars in the world, and Merlin only knew how many lies he'd told her.

Yet, they were sweet, sweet lies. The kind of lies she didn't mind listening to. The kind of lies that bathed her in filth and sludge and dirt to the rest of the world, but that she thought felt like silks and satin, tasted like honey and spring. Sweet, sweet lies. Lies that he whispered into her ear while his teeth grazed her skin, leaving her wanting more.

She bent her head and brushed her lips against his. Her hands trailed all over his body, wherever she could touch, memorising every ridge, groove and plane of him. She pressed her mouth along his neck, biting into tender skin where she knew his pulsing vein was. She could tear that skin away, leave him on the bed, bleeding out and dead within seconds. It would be so easy. So hard.

One hand drifted away from its roaming, drifted to her wand on the bedside table. He never trusted her with it for the first few months they were together. Now, he let her keep it with her, let her point it at him and use it to threaten and hex him. Not that she ever did. And he knew, as he always stood there with that infuriating smirk on his lips. So beautiful, with the perfect face and the perfect lips. So beautiful and so cruel, with his eyes that were ice and disdain.

It was the same, yet different this night. It was the same when she wrapped her fingers around the familiar wand, and drew her mouth away from him before digging the tip of it into his neck. It was the same when he finally opened his eyes and looked at her, the way he had for countless nights now. It was the same silence that stretched between them, a horrible, yawning rift that made her want to put her wand away and beg for his love at his feet.

"Will you do it this time?" he asked, repeated lines, rehearsed words.

She would tilt her head and say 'no', before putting her wand away and revelling in his touch until she was writhing and screaming beneath him.

But not this night.

She tilted her head. "I don't know," she whispered, the out of place words standing out like black against white. He raised an eyebrow, and let his hands run over her thighs. She arched under his touch.

"There's a Muggle story," she said, breath hitching as his hips thrust up against her. "About a mermaid, who fell in love with a human prince." He sat up slowly, pushing against the point of her wand. She yielded, letting him push forwards until he was burying his lips into the crook of her neck, and she was moaning quietly.

"So?" he murmured against her skin, tongue flicking out, tasting the saltiness of it.

"She went to a witch, and a-asked for a potion to turn her human," she paused, dampening her lips as he reached up to cup her breasts. "T-The witch gave her the potion, in exchange for her voice. The p-potion would last for three days." His thumb brushed over her nipple and she whimpered. "If, by the end of the third day, she had not managed to gain the prince's love, she would turn to foam and die."

His mouth moved down to latch onto one nipple, tongue swirling around it. She didn't let her wand slip, though her fingers trembled slightly.

"She met the prince, but he was in love with another, due to be married," she whispered, her tone hushed now. He paused in his ministrations, looked up at her with hooded eyes. Their gazes locked. "On the third day, the day of his wedding, her sisters rose to the surface. They had traded their long, lovely hair to the witch, for her to have a chance at salvation. They gave her a dagger, and told her that if she stabbed the prince's heart with it, she would be a mermaid once more."

He spoke, at last, and his voice was as hushed as hers. "What did she do?"

She dug her wand harder into his throat. His thumb moved on her skin in a circular pattern.

"She turned to foam, and drowned away."

His reply was barely audible, a slither of breath hissed between perfect teeth. "A fool."

He flipped her over then, plucked her wand out of her hands, and put it aside. Her protest was swallowed under his hard kiss.

It was rough, fierce and almost painful. It would leave her with bruises and love-bites, him with more, along with nail scratches on his back and his arms. When they were done, chests heaving but thoroughly sated, she sat up again, sore and aching but determined, and pointed her wand at him.

He had an unreadable expression on his face, an inscrutable look in his eyes. "What will you do?"

She felt the question weigh on her soul. The choice was hers now. Kill him, for salvation, for the greater good, for her family and friends that had died in a distant future. In a different time, a different life. Or drown in the horrors of darkness and misery and pain that he would bathe her in. If she drowned, she would hate it. Hate every second of that delicious torture, hate the way his touch tainted every shred of goodness and light that ever existed inside her, until she was cold and rotten to the core like him. And she would hate it almost as much as she loved it.

Beside her, he watched the beautiful, brilliant, bushy-haired witch that held his life in her hands and saw the decision in her eyes. Saw the moment everything fell into place for her and the steel in her gaze. He'd known it since the beginning, he'd known her choice. Known it since he laid eyes on her and she had glared at him with loathing and disdain that rivalled his own.

She looked at him then, as though she was seeing clearly for the first time. This wizard, who was the epitome of 'tall, dark and handsome'. This Dark Lord, whom she loved and worshipped and hated. Whom she knew had already killed countless people, though he was still so young. Who had two Horcruxes, that he had let her destroy, as though he were indulging a pet. She gripped her wand tighter, white skin stretched taut over her knuckles.

As she said the words, he smirked. She was a fool, he knew, but when she let him kiss her and taste her and let her wand fall from her grip, he wondered who was the bigger fool.

The mermaid who couldn't kill her love, or the prince that would have let her?