Harry left the infirmary feeling smug after his little encounter with Susan. He liked having that kind of control over people, especially when they didn't realize it. But his mind quickly shifted to something more practical. On the way to find Hermione, he couldn't shake the image of Madam Pomfrey using those diagnostic spells on Susan. He'd never seen the old matron flustered like that before, and it got him thinking—if he and Hermione could learn those spells, they could apply them to their experiments, get some real data.
Spotting Hermione near the library, her nose already deep in some book, Harry approached with a grin. "Hermione, I saw some diagnostic spells Madam Pomfrey used earlier. Think we should learn them?"
Hermione looked up, raising an eyebrow at him. "Why? Did you get yourself into trouble again?"
Harry chuckled, shaking his head. "Not quite. But if we're going to keep pushing the boundaries with these experiments, we need to know what's going on under the surface. I'm talking magic flow, body reactions—everything."
Hermione pursed her lips for a moment, then nodded. "That's… actually a good idea. We can look them up in the restricted section, there's bound to be something on medical magic."
They spent the afternoon in the library, finding books that broke down the intricacies of diagnostic spells and the many ways to track magical energy within the body. Hermione, of course, picked up on the theory right away, while Harry skimmed the practical parts, thinking of how useful this could be later that night.
After classes dragged on for the rest of the day, Harry's thoughts kept bouncing back and forth between his plans and what they'd learned. The sun was low by the time he finally gathered everyone for the experiment. When he entered the hidden room he'd arranged for them to use, Hermione, Lavender, and Parvati were already waiting, chatting idly among themselves.
Neville stood awkwardly to the side, fidgeting like he was second-guessing every life choice he'd ever made.
Harry glanced at the clock and frowned. "Where the hell is Ron?"
Neville shifted nervously. "Maybe he's just sleeping in, you know? I don't think he's one for these kinds of experiments."
Harry's eyes narrowed. Something didn't feel right. Ron might not have been the brightest, but he was reliable. He looked at Hermione. "What do you think? Could something have happened?"
Hermione glanced over at the clock, biting her lip. "It's probably nothing. You know how he is—he might've just conked out."
Harry gave it a moment's thought and nodded. "Right. Let's move on without him for now." He turned his attention to Neville, who looked like he was trying to blend into the wall.
"Alright, Neville, we're going to need your help with this," Harry said, his tone calm but direct.
Neville's eyes widened with panic, and he immediately stepped back. "Wait… what are you talking about? I-I'm not sure I want to be part of this."
Harry frowned, genuinely confused. "What do you mean?"
Neville swallowed hard, his face going pale. "You're going to—going to sell my body to them, aren't you? They're going to use that potion on me!"
The room went silent for a moment. Harry, Lavender, and Parvati exchanged baffled looks before bursting into laughter. Even Hermione cracked a smile.
"No one's selling your body, mate," Harry said, shaking his head. "We're not doing anything like that."
"Honestly, Neville," Hermione added, rolling her eyes. "We wouldn't dream of it."
Harry stepped closer to him, lowering his voice to reassure him. "Look, we're just trying to figure something out. A lot of men in this world can't… you know, get it up. We want to see if there's a way to help with that."
Neville looked torn, but after a moment of hesitation, he nodded. "Alright… I guess I'll help. But I'm not drinking anything weird."
Harry smirked. "No potions, promise. Just trust me."
With a sigh, Neville fumbled with his trousers and eventually took them off, standing there awkwardly in just his underwear. He was clearly uncomfortable, but Harry knew he'd come around once things got started.
"Parvati," Harry said, motioning her over. "You're up."
Parvati grinned, wasting no time. She knelt in front of Neville, her hands already working to pull down his underwear, exposing him to the cool air of the room. Neville flinched but didn't pull away.
Hermione stepped in, her wand ready as she began muttering diagnostic spells under her breath. Soft lights danced over Neville's body as she analyzed his magic flow, his blood circulation, and more.
Harry, not wanting to make it more awkward than necessary, turned his back on them for a moment, staring at the clock on the wall. He sighed. This was supposed to be a comparison test between Neville and Ron, but with Ron gone, Neville would have to do for now.
Suddenly, a delighted squeal echoed through the room. "Oh my god!" Lavender's voice was filled with surprise.
Harry turned around and found himself face to face with something unexpected. Neville's cock, to his shock, was rock hard, and Parvati was enthusiastically sucking him off, her lips wrapped around his length.
Neville, who moments ago looked ready to pass out from nerves, was now grinning like an idiot, his hands resting awkwardly at his sides as he let Parvati do her work.
"Bloody hell," Harry muttered under his breath, genuinely impressed. He hadn't expected this at all. "Neville, you're full of surprises."
Neville, grinning sheepishly, said nothing, too overwhelmed by the sensation to respond.
"Go ahead and fuck her, mate," Harry ordered. "Do whatever you want. You've earned it."
Neville blinked, his face flushing red as he looked down at Parvati, who pulled off him with a wet pop, looking up at him expectantly. After a brief pause, Neville took control, lifting Parvati onto the nearby desk and positioning himself between her legs. She spread her thighs eagerly, wrapping them around his waist as he pushed into her with a groan.
While Neville got busy with Parvati, Harry turned his attention to Hermione. "What are the diagnostic spells showing?"
Hermione's brow furrowed as she read the results flickering in the air. "His blood flow is normal. But… there's a spike in his magic. It happened right when Parvati started sucking him off."
Harry raised an eyebrow, intrigued. "A spike in magic? What could that mean?"
Hermione shrugged, clearly puzzled. "I'm not sure. But it seems like something about the stimulation caused his magic to react."
Harry glanced back at Neville, who was now thrusting into Parvati with surprising enthusiasm, her moans filling the room. He couldn't help but grin. Neville, the shy, bumbling Gryffindor, had turned into quite the stud when given the chance.
But his attention quickly shifted as he noticed both Hermione and Lavender staring at him, their eyes filled with unmistakable need. Harry rolled his eyes, already knowing what was coming next.
"Fine," he muttered, unbuttoning his trousers and letting them drop to the floor. Both girls wasted no time, dropping their skirts in turn. Hermione sat up on the desk, legs spread as Harry positioned himself between them, guiding himself into her with one smooth thrust.
Hermione let out a soft gasp, her arms wrapping around his neck as he began to move inside her. At the same time, his fingers found Lavender's wet entrance, teasing her as he pulled her close, capturing her lips in a heated kiss.
He switched between the two effortlessly, his mouth moving from Lavender's lips to her breasts, sucking on her nipples while his hips thrust harder into Hermione. Hermione's body clenched around him as she reached her peak, her fingers digging into his back as she pulled him in deeper, gasping out his name.
As soon as Hermione's orgasm subsided, Harry pulled out and spun Lavender around, pushing her down onto the desk before entering her from behind. She moaned loudly, pushing back against him as his pace quickened. With one arm wrapped around her waist, he pulled Hermione close, attacking her neck with rough kisses as he rocked into Lavender.
The room was filled with the sounds of their heavy breathing, the wet slap of skin against skin. Harry increased his pace as he neared his own release, feeling Lavender tighten around him as her own climax approached. Her body shuddered as she came, her juices spilling down her thighs just as Harry buried himself inside her one last time, groaning as he released into her.
Panting, Harry pulled away, glancing over at Neville, who was still thrusting into a blissed-out Parvati. The sight made Harry smirk.
Once they were all dressed, they gathered in a circle on the floor, still trying to catch their breath. Harry broke the silence first, turning to Neville.
"So, Neville," he began. "Could you always… you know, get it up?"
Neville shook his head, looking embarrassed. "No, I—this was the first time."
Hermione, looking thoughtful, chimed in. "It might have something to do with your magical reserves. You said earlier you felt like there was an ocean inside you, right? It could be connected."
Harry nodded slowly. That made sense. If Neville had a large pool of magic, like he did, it could explain why he was able to perform normally when other men couldn't.
Parvati, still catching her breath
, tilted her head. "But what about that magic spike Hermione mentioned? That's not normal, right?"
Lavender, always practical, shrugged. "Some men get lucky. Maybe today was just Neville's day."
Parvati wasn't convinced. "Let's test it right now." Without warning, she pulled her shirt down, exposing her breasts and pressing them against Neville's face.
Neville, too stunned to do anything else, buried his face in her chest, sucking lightly on her nipples. The group watched in amazement as his cock hardened again, straining against his trousers.
"Well, that answers that," Harry said with a grin. "Neville's completely functional. Lucky bastard."
Neville blushed deeply as Parvati pulled away, looking rather pleased with herself.
But Harry wasn't done thinking. "That magic spike needs more study. We'll need diagnostic spells that can track where the magic is gathering, not just that it's there."
As they began to talk about their findings, Harry turned to Lavender, asking something that had been on his mind for a while. "Lavender, how hasn't the population just… died out, if men can barely get it up?"
Lavender raised an eyebrow, looking surprised. "You don't know? Every man in the world gets an erection on March 15th. It's a biological thing, and their sperm is super fertile that day."
Harry blinked, stunned by the casualness of her explanation. He glanced over at Hermione, who gave him a strange look. "Harry, how do you not know that? It's common knowledge."
Harry rolled his eyes, feeling a twinge of frustration. "No one ever bothered to teach me sex ed, alright? I grew up with Muggles who didn't tell me anything."
There was a brief pause before everyone nodded, giving him sympathetic looks that made him want to groan. Hermione, ever the encyclopedia, explained further.
"It's called the Date of Perseverance. Science says that men's reproductive systems eventually synced up, so now every man in the world hits a 'reset' point on March 15th. Their fertility peaks, and that's when most babies are conceived."
Harry frowned, taking in the information. It made sense, but it also sounded ridiculous. He filed it away in the back of his mind for later.
"Alright, that's enough for today," Harry said, standing up. "We'll decide the next experiment date soon. Let's get out of here."
As they all stood to leave, Parvati winked at Neville. "I wouldn't mind running a few more experiments with you, Neville."
Neville blushed furiously but smiled shyly, clearly flattered by the attention.
Later that night, as Harry was about to drift off to sleep, Neville's voice broke the silence.
"Harry… why isn't Ron in his bed yet?"
Harry's eyes snapped open, and a sudden wave of dread washed over him. His mind raced as he considered the possibilities. Had something happened to Ron? Had someone gotten to him with that potion?
Fear gripped him, and without a word, Harry jumped out of bed, grabbing his wand as Neville followed behind him, both of them rushing out into the dark halls of Hogwarts.