AN: Prompt by PhenomenalAsterisk in Magical Shippers RnD (18+) Discord server:
A is cursed/potioned/hexed such that anyone who touches them gets insta-horny and tried to follow through. B helps them get un-whatevered and is miraculously unaffected by the whatever. Really i just want a reveal that goes, "that's my secret. I'm always horny [for you]"

"Facalimorae!"

Draco's strawberry-red curse connected with Harry's back before he could react. He turned to cast a stunner, a disarming jinx, or something in retaliation, but the ferret had already ducked around the corner. He was too concerned with what happened to give chase. He couldn't feel any pain and he couldn't feel anything weird growing out of his back. Perhaps it left a visual mark of some kind?

Going into the first bathroom he came across, Harry removed his robe and shirt to check his back in the mirror. Nothing. Did the curse not work? Putting his clothes back on, he figured he should go to the library and see if he could find whatever Malfoy sent at him. Hermione might have heard of it too. Fasamorae, or something, Harry thought he'd heard.

As he was leaving the bathroom, he literally bumped into Colin Creevey. And then he found himself pinned to the wall by the younger Gryffindor with their lips connected and a pair of hands working their way towards his pants. He tried pushing Colin away, but the brown-haired boy only tried to come back in for more. Harry had known and considered Colin a friend for the last four years. He knew Colin looked up to him, adored him, and practically worshipped him. He never knew Colin felt this way about him. He only hoped rejecting the boy didn't hurt his feelings too much.

"Look, Colin," Harry started, having to physically hold him at arm's length, "you're a great guy, but I don't see you that way. I'm sorry."

Before Colin could respond, Harry rushed out and down towards the library. He had no idea how the wizarding world viewed same-sex relationships, so he wouldn't be telling anyone what happened with Colin. Hopefully, his friend could find someone that felt the same way someday.

When he reached the library he went straight to the back corner where he knew one of his best friends since his first year often studied. Hermione was there, working on what looked like the essay on the Uses of Valerian Root in Potions that Slughorn asked them to complete.

"Hey, Hermione," Harry took a seat opposite his friend and waited for her to finish the sentence she was writing and look up at him.

"Yes, Harry?" Hermione replied curtly. She was clearly still annoyed he was doing better in potions than she was.

"I was wondering if you might have heard of a spell. Fasamorae, or something like that?"

"Is that another curse in your stupid Prince's book?" Hermione asked with suspicion. She really hated that he hadn't turned the damned book in.

"No, Malfoy hit me with it, but I haven't noticed anything happen."

"Well, I haven't heard of it. Perhaps you should check with Madam Pomfrey." Hermione dismissed him.

"I don't want to bother her if it's nothing. Thanks anyway."

As Harry got up to leave, his hand brushed Hermione's and he was pulled into a searing kiss. For the second time today, someone was initiating very intimate contact. He always thought Hermione was pretty, but he'd always thought of her as a sister. Kissing her felt wrong. Having her hand grabbing at his arse felt even more wrong. Pushing her away, he looked into her eyes and was surprised to see such a burning desire.

"Hermione," Harry began, "I can't do this." As he pulled away, Hermione seemed to start coming to her senses and realised where they were and what she was trying to do.

"Oh, Harry. I'm sorry. I don't know what came over me." Hermione looked worried. She was mad at him, but she didn't want to lose him as a friend.

After assuring her she was forgiven and explaining he cared about her as a sister, Harry left the library. Something really weird was happening.

Over the following week, Harry kept having similar run-ins with way too many people. Most of the situations were too confusing to even begin to make sense of. His best mate's girlfriend, Lavender Brown, jumped him in front of that same best mate. Instead of punching him as he expected, after pulling them apart Ron went in for his turn with Harry. Perhaps they wanted a third person in their relationship? He wasn't going to judge, but he had no intention of joining them.

Others from Gryffindor included Romilda Vane, Ginny Weasley, and Colin's younger brother Dennis. Hermione's face turned beet-red and she buried her face in a book any time she saw him. The other girls had absolutely no shame in their actions and still looked at him with lust-filled eyes from across the room while both Creevey brothers acted as though nothing ever happened.

From Hufflepuff, Susan Bones, Hannah Abbot, Zacharias Smith and one of the quidditch chasers a year above Harry - Cadwallader, Harry thought his name was - tried having their way with him on separate occasions. Smith looked mortified when he next saw Harry, clearly worried the Boy-Who-Lived might have said something. Harry, however, wasn't one to judge and wouldn't be telling anyone about the people who had been jumping him recently.

Unfortunately, sometimes there were others to witness what happened. Daphne Greengrass and Pansy Parkinson were there when Tracey Davis tried pulling him into a broom closet. He escaped only for the same thing to be repeated with Daphne when she began to confront him for attacking Tracey. He adamantly stated that she attacked him before making his escape. He thankfully avoided a repeat with Pansy.

Probably the worst of all was when Snape grabbed his arm at one point. He could have sworn he saw something in Snape's eyes before the Slytherin Head of House demanded him to go to his common room, or anywhere else away from him. It was the weirdest interaction he'd ever had with Snape. He didn't even lose any house points.

Harry couldn't remember anyone from Ravenclaw trying anything. To be fair, he had been avoiding most of them since he learned they were bullying Luna. He secretly had a crush on the quirky blonde, though he was too afraid to ask her out. He didn't think he'd be able to handle losing her as a friend if she rejected him.

The... interactions... with others that week is what led Harry to spend his time outside of classes hiding away in the astronomy tower. No one would find him there. He thought he worked out yesterday what was happening and immediately went to Hermione.

He mostly wanted to give her a possible explanation to what came over her in the library at the start of the week, and she was also the only one he trusted to test this theory. He had been right, and Hermione felt much less embarrassed by the whole thing. Anyone who touched him became instantly aroused for him specifically to a near-uncontrollable level. She even offered the suggestion that this had something to do with Malfoy's curse he mentioned.

He believed she might be right.

It was in the astronomy tower that Luna of all people found him. Knowing what he did about the curse, he didn't know how he would react if Luna tried anything. He didn't want to reject her but at the same time, she wouldn't be in control of herself and that wouldn't be right. So he backed away from her and told her what was happening.

Instead of leaving him alone as he hoped, she smiled and stepped closer; close enough to place her hand on his shoulder. Harry was ready to push her away, as reluctant as he was to do so, so it came as a surprise when Luna held herself back. The look in her eyes didn't change as Snape's had and she wasn't trying to distance herself. Whatever Malfoy's curse had done, Luna seemed to be immune to it.

"What did you say the curse was?" Luna asked him, "Perhaps I've heard of it."

"Fasamorae or something like that. I haven't found it in any book." Harry gave her a defeated smile. He'd given up halfway through the week of finding a counter-curse, and he was worried about going to see Madam Pomfrey about such a thing.

Luna hummed. "Facalimorae. I've heard of it." she then pointed her wand at Harry and muttered the counter to it, "Finite Alimorae."

Harry blinked in surprise. He really only had to find Luna to end the damn curse? Now he only needed to go find someone to test if it worked, and- wait a minute...

"Luna?" Harry looked at the girl curiously. "How were you not affected by it at all?"

Luna looked into his eyes for a moment as if she was making a big decision. Then she spoke.

"Oh, it's really quite simple Harry. The spell caused anyone who touched you to temporarily feel a strong desire to be intimate with you. It also seemed to have removed most of their self-control. I've been fighting the urge to jump you and have my wicked way with you ever since the start of last year. I was simply curious to see if the curse affected me since I already felt that way about you." Luna stated as casually as she would if she was discussing the weather.

Harry stood in shock while his brain processed that information. "R-really? Y-you want to be with me... like that?"

"Yes, Harry. More than anything." Luna was pleased. He hadn't rejected the idea of being with her yet and even seemed to like the idea.

"In that case, would you be interested in going on a date with me on the next Hogsmeade weekend? We can take things slow and see what happens."

"I'd love to, Harry." Luna smiled. She was one very happy witch.

Talking aloud to herself in earshot of Malfoy about the spell she created was the best mistake she ever made. At least she assumed that's what happened. There was no other way Malfoy could have known of it. Now if only she could work out the problems with it. The spell was supposed to only affect the caster, and it should have enhanced her already strong feelings for Harry when she touched him.

Another two and a half years of Arithmancy would hopefully be enough to accomplish that. She loved the feeling of just barely being in control of herself around Harry but after a year of not doing anything, she had amazing levels of self-control. That's what the spell was meant to achieve for her.

She laughed internally, imagining if the spell worked properly. Malfoy's reaction to Harry when it ended would have been priceless.