Author's Notes: Hmm, how much do you like this story, my dear thousands of reviewers? Yes, this is sarcasm, in case you were wondering.

Chapter V

Thursday morning.

"Mr Weasley!" Professor McGonagall's tone was outraged as she looked at Hugo from behind her desk.

"No! No!" he retorted heatedly. "Honestly, Professor McGonagall, you need to listen to me. She feels like she's been kept prisoner in a fish tank! I should owl my mother! She'd be furious to know that her niece is being kept in an unsuitable environment like that. I'll tell her that that tub is way too small for her, she's all covered in cuts and she was bleeding! I had to Heal her… yes! She was bleeding into the water! And she asked me to free her! She asked me to bring her to the sea! She's not happy."

Professor McGonagall's face went from shocked at Hugo's heated tone, to surprised, to plain furious. "Mr Weasley! You entered the tub!" she gasped.

Hugo sat back slowly on the chair across from her, suddenly well aware of his slip. "No," he replied, trying to sound nonchalant.

The Headmistress' eyes narrowed. "Then how did manage to understand her without putting your head into the water?" she asked curtly.

Hugo's shoulders hunched. "Alright, I might have taken a swim with her," he replied, trying to sound as contrite as he could. "But I was completely safe, I swear. And she was grateful when I Healed her."

"Mr Weasley, have you not listened to a word your mother said the other day?" she asked him severely. "Mermaids are extremely strong, and they can be vicious. If her mating instinct should suddenly take control of her, what do you think would happen?"

Hugo sighed, but didn't reply.

"Well?" she urged him.

He looked at her and blushed. "She would mate me, then drown me," he replied in a murmur.

"Exactly!" exclaimed Professor McGonagall.

Hugo exhaled and crossed his arms. "But she's not happy," he continued a bit less forcefully than before, "that place is too small…"

"Mr Weasley," sighed the Headmistress, "what you have to remember is that Miss Potter's condition is temporary and highly unstable. What would happen if she were to change back suddenly in the middle of the night? While she's sleeping at the bottom of the tub? Were that tub any bigger, she would probably drown. Like this, at least, she can find her way back to the surface relatively quickly, wherever she is."

Hugo opened his mouth to reply something, but couldn't seem able to find anything to say at all. The Headmistress made a lot of sense indeed. Suddenly, his head filled with terrible images of Lily changing back to herself and drowning at the bottom of the Prefects' tub. "But… but those rocks are too sharp… and there are too many…"

"We've recreated her natural habitat, Sirens are graceful and they usually manage to swim even into the smallest places without bumping into things," she told him, before eyeing him sternly. "She does however have a tendency to get excited quickly," she told him, "especially, apparently, when she's with you, since Madam Pomfrey always finds her in a particularly bad state in the evening, after you visit her."

Hugo blushed crimson. It was true, she was particularly restless when he was there, swimming in circles, jumping out of the water, kissing him against the rocks…

"It would probably be for the best if you were not allowed to see her until the moment she regained her human mind," she told him calmly. "For both of you, I've heard you've been very distracted lately, Mr Weasley."

Hugo looked at her, eyes wide in surprise. He suddenly felt as if he couldn't breathe at the thought of not being able to visit Lily every day. He felt as if McGonagall had punched him in the guts, and she had a bloody strong right.

"No, no, no," he said resolutely, shaking his head, "I cannot not see her. I have to see her. And she does too. She's so happy when she sees me, I swear, that lights up her day. And mine. Like, I could be sick if I wasn't allowed to see her. Honestly… please, Professor McGonagall… don't forbid me to see her."

Professor McGonagall stared at him for a long moment, eyes narrowed behind her lunettes. "Her Mating Magic is really strong," she told him finally, "many sailors have died in the past because of mermaids' magic."

"I won't die," he replied with a hopeful smile, "she won't kill me, I'm sure, she… she wants me to marry her, I mean, mermaids don't kill their husbands."

Professor McGonagall's eyes narrowed even more. "Oh yes, Mr Weasley," she sighed, "how many times does Newt Scamander talk about mermaids' husbands in Fantastic Beasts and Where to Find Them?"

He swallowed. "Never."

"I wonder why," replied Professor McGonagall with a growl.

Hugo lowered his eyes. "But she's so beautiful," he sighed, "and so sweet. And her tail is so smooth, and she's so good at kissing…" He smiled dumbly, not quite caring that he was telling this to the Headmistress. He closed his eyes for a moment, and all he could feel was Lily and her lips and the sloshing of the water around him and the bubbles that tickled his face…

"Mr Weasley!" snapped Professor McGonagall forcefully. She sounded as if she had already called him a few times.

"Yes?" he replied, shaking off those thoughts.

She sighed. "Of course mermaids are skilled in the art of seduction," she told him, "that's what they do, that's what they've been doing ever since the beginning of time. Seducing men, sailors most of the time, to procreate and then kill them; just because they didn't need them anymore."

"But when she is back to herself, she won't want to drown me anymore, right?" asked Hugo hopefully.

"No, but clearly she's not back to being herself yet, Mr Weasley," she replied patiently. "And don't delude yourself; when she goes back to being herself, her Mating Magic will dissolve and you won't find her either attractive or alluring anymore."

"But Lily is attractive!" he replied stubbornly. "I mean, she's always been. To me she's much prettier than… than Victoire, and you know how everybody always babbles about Victoire… right?"

Professor McGonagall cocked an eyebrow at him, as if she had always ignored that everybody babbled about Victoire. "Of course, Mr Weasley," she replied slowly. "I have to warn you that in case you've harboured feelings for Miss Potter prior to her change, you might find those sentiments slightly intensified even after the magic will disappear." She smiled reassuringly and added, "Nothing that you won't be able to push to the back of your mind at any time, though."

Hugo looked at her, trying to look supremely outraged instead of slightly troubled that that might just be the case. "I haven't harboured feelings for Lily!" he grunted. "Can I just remind you that she's my cousin?"

"Can I just remind you that the Black family tree is filled with marriages amongst cousins?" she replied as if that was a perfectly fine argument.

"Can I just remind you that ninety percent of the Blacks were completely out of their minds, Professor McGonagall?" he replied curtly.

She looked at him, unimpressed. "Can I just remind you, Mr Weasley, that you descend from the Blacks?"

He darkened and didn't find much to reply to her. Every hour that passed, Hugo found something that he liked about Lily, and every time he did, he was a little surprised to remember that he had already noticed that about her.

After all, she was beautiful and he had found himself staring at her as she threw the Quaffle around during trainings. Of course he had always told her that he was observing her movements to see what she was doing wrong, but he probably should have looked at her arms and not stare at her chest when she flew around. He smiled at the thought that he had now seen Lily's chest without a Quidditch uniform to cover her – or any other piece of clothing at all – and that he had even felt them all over his skin. He sighed. Suddenly, he felt very dizzy… what with all that Mating Magic in the air and his head swimming most of the time.

"Now," the Headmistress said when he didn't reply. "I have things to do, and I'm sure you do too, Mr Weasley."

He looked anxiously at her. "Can I visit Lily?" he asked hopefully.

Professor McGonagall sighed. "Yes, you can," she replied, "but don't put yourself, or her, in any kind of danger, is that clear?"

"Like water!" he replied, jumping up from his chair. "Thank you, Professor McGonagall!"

"Mr Weasley, I mean it, don't do anything—"

But Hugo didn't hear what he shouldn't have done, for he was already hurrying down the stairs and towards the Prefects' Bathroom.

oOoOo

Thursday afternoon.

The water was nice and warm as Hugo dove into the tub. He had foregone his underwear for his actual swimming trunks and had even brought a towel and flip-flops with him this time.

He opened his eyes just in time to see Lily swimming quickly towards him, and she was on him before he could even take his first mouthful of air from the bubble around his head.

"Hello, my brave sailor," purred Lily as she wrapped her tail around his waist and started to shower him with kisses. "I missed you."

He slid his hands on her back, and pulled her even more tightly against himself, kissing her back for dear life. "Hello, my beautiful Siren," he replied with a smile in his voice, "I missed you back."

She looked at him and fluttered her eyelashes flirtatiously, before settling on his lap as he plopped on a rock, his feet dangling in the water. "One month and twenty-nine days before we get married," she told him, her arm resting on his shoulders. "I've counted them."

He chuckled awkwardly. Bloody hell, she was tenacious.

"Great," he coughed. He wanted her, he wanted to spend every second of his upcoming life with her, and he wanted to spend all the time with his fingers running over the smooth curve of her spine and with his lips exploring every inch of her skin… Nevertheless, he wouldn't be unhappy if he delayed her thoughts of marriage of another few months or years…

He tried to find something to tell her to distract her. But it was a difficult task, what with her delicate breasts pushed so deliciously against his chest, and her lips all over his face and neck, and her hand inside his—

"Hey!" he spluttered, grasping her wrist before she could wrap her fingers around him. "Wait a second!"

She blinked, probably without understanding, but let him bring her hand back up between them. "What?" she asked innocently, placing her fingers on his chest.

He tried to look stern. "That's not how respectable mermaids behave," he told her. "Now, kisses and little touches are more than fine, but you can't just do that without warning." He pressed his lips together, feeling troubled, more than anything, about giving a rather poor performance rather than because of what surely would have happened had he let her have her wicked way with him.

"But you like it," she pointed out.

He liked it. He liked it a lot, and from the way his trunks were tenting, he wouldn't have been able to lie to her. "Yes," he replied with a groan, "but I shouldn't like it."

She giggled, probably noticing the absurdity of his words. Her hand started to descend slowly towards his trunks again, but he grasped her wrist and decided that the best way to distract her was to kiss her until he had no more air in his lungs.

She seemed happy with that arrangement, because her hand rose suddenly and she wound her fingers in his hair, devouring him like only a mythological creature, whose sole aim in life was to attract men and have sex with them, could do. She pushed all of herself against his stomach and his groin, giggling when she sensed his groans of delight, and rubbing herself in circles against his less and less subtle erection.

He closed his eyes and ran his fingers in her silky locks. Everything in her seemed perfect, she was the embodiment of all his desires, even those – or probably especially those – he didn't know he had. From her big blue eyes, to her flaming hair, to her smooth skin and her colourful tail. And her voice was mesmerising, and he could hear it even when she wasn't talking, he could hear it in his dreams… she was whispering his name on a beach as the waves crashed over his prone body…

Lily's lips moved from his mouth to his jaw. She unwrapped her tail from around him and slowly floated between his legs, kissing her way down to his chest.

Hugo sighed as he opened his eyes and looked at her. She moved so sinuously, as if she was dancing underwater, she skimmed her hands all over his sides and her mouth pecked his skin around his navel and then her fingers were at his trunks again and Hugo knew somewhere in his brain that he should have stopped her again, but he wasn't quite sure why anymore.

She smiled up at him as her hands worked on the elastic band of his trunks, and he was just about to nod his agreement to whatever she wanted to do to him, when her blue eyes turned quickly black and a feral expression painted over her face.

For a moment he thought that she was going to drown him without even mating him first. In that moment, he felt highly offended by such an outcome.

But when she jumped up like a spring and threw herself towards the surface, almost slapping Hugo in the face with her fins in the process, he just blinked in confusion.

He was snapped out of his state by cries and splashes of water coming from above him. He looked up and saw Lily trying to push herself out of the tub, her hands grabbing on the tiles as if she was trying to reach something. A lock of long, blonde hair floated gracefully in front of his face and towards the bottom.

Hugo pushed himself on the rocks and let the thrust of the water help him reach the surface. Lily's tail was sloshing water right and left and he could barely see what her arms were doing; but, over the splashes, Hugo could see a tall figure standing near the tub and trying to fend off Lily's assault.

He wondered if it was some student who had broken the rules and come in there to have a look at the mysterious inhabitant of the Prefects' Bathroom, and he felt a ferocious desire to grab them and throw them into the tub and let Lily have her way with them. He grasped a rock and emerged from the water, only to find his sight fog up as Lily let out another inhuman cry.

"Ouch! Damn it!" he muttered, as he scrunched up his eyes and proceeded to cover his ears until Lily decided to stop her screeching – or whatever that was.

"Damn it!" echoed a voice that he recognised. "What the hell is your problem?"

He cracked an eye open and found himself staring at Victoire, who looked positively livid, hands over her head and eyes sending daggers towards him and Lily.

"Vicky!" exclaimed Hugo with a grin, as he pushed his hands on the edge of the tub and jumped up, sitting on it.

Lily's ferocious cries promptly changed in her heart breaking, dolphin-like mewls, she swam to him and threw her arms around Hugo's legs, preventing him from going to greet Victoire.

"Lily, it's alright," he told her gently, placing a hand on her head, "it's just Vicky, she's harmless."

A snort came from behind him and Lily, snarling, bared her teeth and looked at their cousins. "Veela!" she growled. "Veela, bad!"

He nodded thoughtfully, and turned towards Victoire. "She probably can sense your—shite!"

"She can sense my what?" snapped Victoire outraged, but Hugo had already turned back towards Lily, eyes wide and hands going to her face to make her look up at him.

"Lily!" he exclaimed breathlessly. "Lily, you're talking!"

"Veela!" she repeated. "Veela, bad! Mermaid, good!" She smiled, suddenly looking very innocent. "Mermaid good, Hugo?"

"Mermaid best," he told her with a laugh. "Oh damn it! You're really talking! I have to tell that to Madam Pomfrey! I bet you're that close to being back to normal!"

"You're kidding, right?" asked Victoire haughtily. "She's just torn a lock of hair from my head! How is that normal?"

He glanced over his shoulder at his older cousin. She was pointing at the side of her head, but she had so much hair that he couldn't really notice a difference. He wasn't sure that would have made her feel any better about it though.

He looked back at Lily, still grasping his legs as if he was about to walk away any minute, and she would have died if he did. "Lily," he said severely.

She pouted, looking slightly ashamed. And Hugo couldn't help thinking that that too might have been considered an improvement, after all.

"Lily, why did you attack Victoire?" he asked her seriously.

"Veela bad!" she repeated, baring at teeth, before rubbing her face all over his lap. "Hugo mine! Not Veela!"

He looked at her, surprised. "Oh, oh no," he hurried to say. "I don't like Victoire! No, no… eeew! Victoire, bleah! No, Victoire. Victoire ugly!"

"Hey! I think she got it!" snapped Victoire sourly.

He grinned sheepishly at her. "I was just trying to make it easy for her," he told her, before adding, "Bloody hell, Vicky, she's talking! I mean, she's talking out of the water! She does sound like Lily used to sound, doesn't she?"

Victoire looked from him to her, and took a step towards the tub. Lily growled at her, snapping her teeth in their cousin's direction.

"Oh yes," said Victoire dryly, circling the tub to come to stand on the opposite side. "Especially when she growls like that or when she tries to make our eardrums explode."

Hugo darkened. "Well, you weren't here on Sunday," he told her, "I can assure you that she was nowhere near being this civil."

Victoire cocked an eyebrow at him. "You do know what civil means, right?"

Hugo rolled his eyes, he loved Victoire, but the more she talked like that about Lily, the easier it was for him to picture her at the bottom of the tub.

He closed his eyes and shook his head, where was that thought coming from? He cracked an eye open and looked at Lily. Was that her thought?

"What are you doing here, Vicky?" he asked her, trying to sound cheerful. "What an unexpected surprise!" He lowered his hand and grasped Lily's upper arm when he felt that she was about to throw herself towards the other side of the tub and probably trying to tear more of Victoire's hair.

"I came for an interview for a teaching position," she replied, "and since I was already here and Aunt Ginny had told me everything about your misadventures, I thought I'd pop in to check how the mermaid and her mate were doing."

Hugo tried to smile when she called him Lily's mate, but Victoire didn't seem to be wanting to joke about it.

She folded her arms across her chest and looked pointedly at him. "What were you doing?" she asked sharply.

"When?" he asked, his voice a low croak.

Victoire took a deep breath. "Before the Little Mermaid threw herself at me as if she was a Kraken," she replied, "I was trying to attract your attention, but you seemed pretty busy down there." Her eyes lowered to his lap, and he was pretty sure that she wasn't looking at Lily.

He suddenly felt very self-conscious. He tried to close his legs, moving his half-hard cock in a less prominent position. "I… we… we were just talking," he replied, feeling his face burning.

Victoire flared her nostrils just like Aunt Fleur did, when Uncle Charlie would put his dirty boots in her living room. "Oh yes," she replied icily, "you were using your mouths quite a bit."

Hugo sunk his teeth into his bottom lips. "I… Vicky, I swear… we just…"

She raised a hand near her face to stop him. "I know," she said calmly, "it's the mermaid's Mating Magic. Aunt Hermione was very concerned when she explained what it means, she asked me to check that you'd keep yourself safe and stay far from the water." She pursed her lips as if to question what she should have told to his mother.

Hugo looked down at Lily, she was staring at Victoire like a cat would gaze upon a mouse, ready to jump and devour it. She was moving her tail left and right under water and Hugo could feel the movements she made against his legs. He looked back up at Victoire. "I'm totally safe," he told her with a smile, "you can tell that to my mum."

"Hugo, you're taking a dip with a beast that is classified as Dangerous by Newt Scamander," she replied matter-of-factly.

Hugo gritted his teeth. "She's not a beast!" he snapped. "Don't you dare call her that!"

Victoire seemed a little taken aback by his harsh tone, but her surprised face darkened almost immediately. "She's not Lily either," she replied curtly, "not yet, at least."

"Lily!" cried Lily at that moment. "Lily! Lily!"

Hugo stretched his lips into the smuggest smile he could muster. "I think she answered for herself," he told her.

She shook her head. "You're impossible to talk to," she told him, "clearly your head is swimming in her magic, and clearly you don't even understand how dangerous your behaviour is." She scowled him. "I just want you to remember that if you let yourself be overpowered by your desire, and something terrible happens to you, once Lily is back to being human, she will never forgive herself for having harmed you."

Suddenly, Hugo darkened and lowered his eyes. He hated the fact that Victoire's words made perfect sense even when he really didn't want them to. But nothing bad was going to happen to him, he was sure about that! Lily had had the possibility of killing him more than once already, and she had never even tried to harm him. Alright, she had, but not in the past two or three days anyway…

"Lily," he called her forcefully, pulling her to him and squeezing her arm.

She let out a high-pitched cry that had little of human, and looked at him with confused eyes as if he was hurting her and she didn't know why.

He darkened even more. "Lily, I need you to focus, okay? Can you do that?"

She nodded and he let her arm go. She started to massage her flesh where his fingertips had left red marks.

"Do you want to harm me?" he asked curtly. "Do you want to mate me, and then drown me?"

She looked torn and seemed to be either unable to understand his question or to decide what to reply.

"Lily?" he urged her, he could feel Victoire's eyes on them, and he just wanted to show her that he was right.

She bit her bottom lip, then her eyes became wide and scared again, her tail started to move almost nervously under the water. Finally, she made a graceful pirouette and dove into the water, disappearing through the rocks at the bottom of the tub.

"Does that answer your question?" asked Victoire calmly.

"Yes," he replied seriously, his eyes fixed on the point where Lily had disappeared. "It answers it, thank you very much." He raised his eyes on his older cousin.

Victoire shook her head. "How does it answer it? What does that even mean?"

His chin rose defiantly. "It means that she doesn't want to harm me," he replied as he dove into the water behind Lily.