This is my first contribution to the ML fandom. This is my first fic that didn't take longer than a week to write, in fact I did it in a couple of hours! It's kind of a milestone for me.
This isn't proofed at all so please inform me of any errors thanks :)

"Hi, Mrs Cheng," Alya called as the door opened, revealing a short Chinese woman.

"Hello Alya," Sabine replied kindly, ushering the blogger in and shutting the door. "I think Marinette is in her room, but I'm not sure if she's asleep or not."

"Thanks!" Alya hugged Marinette's mother quickly, and raced up the stairs, eager to tell her best friend of the news she had received late last night.

Alya had been editing some videos for the Ladyblog in her room, when she heard a chime coming from her computer. It was a notification for a message to her blog.

Hey Alya, it read. I was walking down the Seine tonight and guess what I saw? I SAW LADYBUG AND CHAT NOIR MAKING OUT! The message also included a picture – that was clearly not photoshopped – of the two superheroes perched on a roof, and kissing.

Alya had shouted in glee. She did a brief happy dance (after all, she was allowed to show some excitement at her two idols getting together) and quickly checked to see if anyone else had spotted (hah!) the duo.

And they had. Alya had gathered all the photos she could find, and piled them into a single blog post, titled: Ladynoir is finally canon! She stretched her fingers, and prepared to type.

But then she had remembered Marinette, and had to tell her before the whole world could see. Marinette deserved to know first, because she was Alya's best friend. Alya vowed to go to her house first thing in the morning to tell her of the riveting news.

And so when she finally was pushing open the trapdoor to Marinette's room, she was bursting in joy. All that joy quickly dissipated when she saw what Marinette was doing.

Marinette Dupain-Cheng was kissing Chat Noir.

"OH MY GOD," Alya yelled, incapable of saying anything else. The two quickly sprung apart, Marinette sitting on her bed, and Chat Noir awkwardly standing next to her. "Oh my god," Alya whispered again.

"Alya," Marinette said calmly. She carefully walked over to where Alya was standing by the open door. She shut it gently, and then faced Alya. "It's not what you think."

Alya's mouth opened and closed several times, before she pinched her lips together and closed her eyes. "What the hell, Marinette?" she said quietly. Marinette shifted uncomfortably, not offering an answer. "You've been dating Adrien for, like, six months now! Do you even regard his feelings?"

Marinette's head shot up. "I do!"

"Really?" Alya whispered dangerously. "Then why are you kissing Chat Noir of all people?" She gestured to the silent leather-clad boy. His face was red.

Alya whirled on him. "And you!" she yelled. He held up his hands (paws?) in defence, an uncharacteristically scared expression on his face. "Yesterday people saw you with Ladybug!" Chat raised his eyebrows, for some reason glancing at Marinette sheepishly. "You guys are together, right? So why are you kissing Marinette?" Alya asked heatedly, before realising that Chat Noir was a superhero, and could likely kick her arse.

"Alya, maybe… maybe you shouldn't jump to conclusions," Marinette murmured weakly.

"Jump to conclusions?" Alya repeated, shaking her head. "I just saw you two kissing each other! What is Adrien going to think, Marinette?" Alya took out her phone. "You know, maybe I should just call him now!"

"Uh, Alya, I don't think that's such a good idea…" Marinette sounded worried. Good, Alya thought viciously. If she was going to cheat on her boyfriend, she should be worried.

Alya pressed the green button on her phone. A few seconds later, a sharp ringing cut through the room. Was it coming from behind Chat Noir? Marinette looked at Alya expectantly, as if waiting for her reaction.

The ringing ended, and a cool female voice issued from Alya's phone, telling her that Adrien had not picked up the phone. Alya's eyebrows raised as she made the connection.

"Marinette?" she asked. "You have Adrien's phone?" She looked at Marinette, who was biting her lip, but also looking a little relieved. "I mean, I know you stole his phone once before, but again?"

Chat narrowed his eyes. He eyed Marinette, who was refusing to look anywhere but at Chat, a blush on her face.

A few seconds passed with Alya looking angry and Marinette biting her lip. "I'm going to tell her," Marinette said suddenly, looking Chat in the eyes.

"Are… are you sure?" Chat asked concernedly.

Alya looked between them. "Tell me what? That you're cheating on your respective boyfriend and girlfriend? Because I know that already."

"I have to," Marinette said determinedly, ignoring Alya's previous comment. "But you don't have to if you don't want to." Chat shook his head. Marinette nodded once, then turned on Alya. "Alya, I have to tell you something, but don't freak out."

"Freak out? Why would I freak out?" Alya's previous wrath was put aside briefly for curiosity.

"I'm Ladybug."

"And I'm Adrien!"

Alya gaped, staring at the two, who had spoken with straight faces. She rushed to Marinette's bed and sat down heavily. "What?" she whispered. Then she straightened. "Don't lie to me just to clear your names! I thought you were my best friend, Marinette!"

Marinette looked at her, mouth open, tears forming in her eyes. Alya might have gone a little too far with that comment. Chat Noir stepped closer to Marinette, putting a hand on her arm, glaring at the ombré-haired girl.

Suddenly, Marinette brought a hand to her ever-present purse, opened it, and yelled, "Tikki, transforme moi!" A small red… thing flew into Marinette's earrings. Alya shielded her eyes from the bright pink light, thinking, maybe Marinette was telling the truth. In Marinette's place, Ladybug was standing, looking at Alya apologetically.

Another flash of light later (this time green), Adrien stood where Chat Noir was previously. He rubbed a hand on the back of his head, smiling awkwardly. A tiny black creature had popped out of his ring, and now floated beside him, for some reason grumbling about cheese.

Alya didn't realise her mouth was open until Ladybug – Marinette – closed it for her, mirroring the instances when Marinette ogled Adrien.

"What the hell," Alya muttered inaudibly, dropping her head in her hands. "I can't believe this is happening."

Ladybug turned back into Marinette, and kneeled by Alya's feet in supplication. "I'm sorry," she said, tears rolling down her cheeks.

Alya looked up in surprise, forgetting the situation as she saw her friend crying. "Why are you sorry? I'm the one who jumped to the wrong conclusions."

"I – I… I lied to you." Marinette sniffled. "About being Ladybug."

"Yeah, you did," Alya said sourly, remembering what had just happened.

Adrien – Chat Noir – the only one who had a sufficient grip on his emotions, spoke up, "Alya, I know you're upset, but we had to keep it a secret! If Hawkmoth finds out who we are…"

"I wouldn't tell anyone!" Alya said, looking at the model, hurt.

"We know that," Marinette said gently, wiping her tears. "But Hawkmoth might have ways of finding out, and then he'll hurt you!"

"I guess," Alya mumbled. They sat in silence for a few minutes, processing all that had happened.

"So…" Adrien said. "I guess the cat's out of the bag, huh?"

Marinette groaned. She threw a book that had been conveniently lying around at her boyfriend. Adrien caught the book with cat-like reflexes. Which Alya supposed the boy actually had.

"Why did you come here, anyway?" Marinette asked.

Alya chuckled. "Well I had found a huge scoop on Ladybug and Chat Noir last night," she said.

Marinette raised an eyebrow. "Oh really?"

Alya nodded. "Several people saw them making out by the Seine yesterday," she said in a sing-song voice.

Marinette glared at Adrien. "This is all your fault, alley cat. Now everyone'll find out we're together."

Adrien clutched his chest, stumbling back a few paces. "I'm so sorry, my Lady!"

Alya gawked at the two, who were flirting casually. I am never going to get used to this, she thought. She then remembered what she had planned to do that day. She took out her phone, opened up her blog, and found the queued post she had made last night. Think of this as revenge for not telling me, she said in her mind, as she pressed 'post' on her screen. Soon the whole of France would find out that Ladybug and Chat Noir were totally a thing. And maybe Alya could get some exclusive photographs of the two.

All in all, Alya was glad that two of her closest friends were, in fact, superheroes. She just hoped that Nino didn't have a secret either. That would be too much.

BONUS (because I love thelastpilot's headcanon that Nino will receive the turtle miraculous):

"What the hell do you mean that you've got a secret, Nino?" Alya asked incredulously.

"Um," Nino said, licking his lips. "I'm Tortue Marine."

"You've… got to be kidding," Alya whispered. If he wasn't kidding… then all of her friends would be superheroes. And she didn't figure out any of them.

"Wayzz, transforme moi!" Nino yelled. There was a green flash of light, and lo and behold, there was Tortue Marine. "Um, Alya?" he asked, looking over to see Alya had collapsed onto the ground.

Fin! I kind of liked the fic, and I think Alya *would* get angry at Marinette for 'cheating' on Adrien. My headcanon is that after Mari and Adrien start dating (under entirely questionable circumstances) the four all become one friendship group.

Oh and I'm really sorry for the bonus thing, I'm kind of sleep deprived and was going through the Jade Turtle tag on tumblr... By the way Tortue Marine is google-translate french for turtle, and I know it's feminine and I know I've probably ruined the french but oh well

Thanks for reading!