You wouldn't think she was an aggressive or even competitive person. That's what Adrien had thought.

Sweet Marinette, with her bunches, pink capris and tendency to blush.

So he was surprised, to say the least, when she volunteered for Kim's Arm Wrestling Challenge.

Though he seemed to be the only one. Kim, for his part, immediately paled.

"N-no. That's OK."

But Alya had already blocked his escape, a wicked smirk on her lips.

"Uh-uh. You issued the challenge. You've got to see it through."

Amid cheering and cries of "Kick his ass, Marinette!", Adrien turned to Nino in confusion.

"What's going on?"

"Oh!" Understanding dawned. "Right. You don't know." He chuckled and shook his head fondly, to Adrien's annoyance.

"Yes, and I still don't know, and I won't until you tell me. What's going on?"

Nino just grinned. "Just watch. You'll see."

Adrien glanced over his shoulder. Marinette and Kim were seated now, facing each other.

Alya was standing behind Marinette, rubbing her shoulders and whispering in her ear, like a trainer at a wrestling match. It certainly looked like she was gearing up for a fight. Her eyes were narrowed, fixed almost predatorily on her opponent, lips parted in anticipation.

Cute.

The thought popped into his head, and Adrien immediately chided himself for it.

Not that it stopped him from following Nino as they joined the rest of the class crowded around the picnic table. Even Chloe and Sabrina were watching, albeit at a distance, while pretending to play on their phones.

Kim, on the other hand, looked nervous. Alix and Max were standing behind his seat too, though in their case, they looked more like guards, posted to impede his escape. He tried anyway.

"Come on, guys. I was joking. Just let me – "

"No way," Alix said, letting a hand fall heavily on his shoulder. "You said if anyone could beat you at an arm wrestling match you'd kiss Mme Bustier. And now you have a challenger."

"But, guys," he whined. "Marinette – "

"I'm afraid you should have thought of that before," Max interjected. "Now, would anyone care to bet? I calculate the odds are two to one in Marinette's favour. Who'd like to bet against me?"

Kim scowled, and scowled harder when no one volunteered.

Alya grinned and rubbed her hands together. "Suck it up, man. It is on!"

Marinette answered her smirk with one of her own, planting her elbow firmly on the table and holding out her hand expectantly. Her expression was determined, confident and strangely familiar…

As Adrien wracked his brains, the crowd drew a collective breath in anticipation. It really was like being at a wrestling match. Or, at least, so Adrien imagined.

Under the peer-pressuring gaze of his whole class, Kim reluctantly placed his elbow on the table and took Marinette's fist.

It was over astonishingly quickly.

Adrien had expected some struggle, some back and forth, and despite the reactions of the rest of the class, he hadn't expected Marinette to actually win. She was so small, after all. So slender and delicate looking compared to her much larger classmate.

But Marinette, it seemed, had arms of steel.

Without appearing to exert any effort – if anything, her smile actually widened – beyond a tightening of her grip, she flexed a bicep and pounded Kim's whole arm into the table.

The entire class erupted into cheers, while Chloe and Sabrina tittered, Kim slumped and Adrien gaped.

Nino, laughing, nudged Adrien's shoulder.

"See? What did I tell you? Marinette's hella strong."

"You didn't tell me anything."

But Nino wasn't listening, having abandoned Adrien to fist bump the victor, while Alya held her other fist in the air like a champion, to general, loud approval.

"God, that was funny!" Alix shouted over the noise. "Awesome, Marinette! Totally awesome."

Marinette grinned back, flushed with success.

"Thanks! But are there any other challengers?" She said it jokingly, but a hush descended over the group anyway.

"What!" Alya exclaimed, pantomiming surveying the crowd. "Is there no one? No one daring enough to take on our reigning champion, Mlle Marinette Dupain-Cheng?"

After a beat, Nino raised his hand, to everyone's surprise.

"Oh, no. Not me," he said hastily as Marinette's gimlet eye fell on him. "But…" his smile widened craftily. "I bet my man Adrien, here, can beat you," he continued, clapping a hand on Adrien's shoulder.

Adrien stared at him. "What? Me?"

Nino nodded confidently. "Hell, yeah, dude! I've seen you in the locker room. I've seen you in gym. You are ripped."

Adrien waited for someone to laugh. Surely, any second now, someone would shout "April Fools!" (though it wasn't April). Because he was sure, certain¸ that as far as everyone else was concerned, he was just a model, just a pretty face.

But the boys in the class only looked thoughtful, while the girls looked intrigued.

All except Marinette, who seemed horror struck.

"What? No! I can't fight Adrien,"

She could have been talking about kicking a kitten, and Adrien might have been offended if he hadn't agreed. He couldn't fight Marinette. Sure, she seemed to be strong. But he was a superhero

"I don't know," Alya said slowly, looking as if Christmas had come early. "You did issue a challenge. And we didn't let Kim off the hook. So…"

And that was how Adrien found himself pressed into Kim's vacated seat as Marinette was pushed back down into hers.

"But I was joking!" she cried desperately.

No one appeared to be listening.

Instead, money changed hands rapidly as an impromptu betting ring emerged.

"They're betting on us?" Adrien muttered, shocked and a little embarrassed.

He hadn't addressed the comment to anyone in particular, but Nino answered anyway, flopping onto the bench next to him.

"Yup! Don't worry, dude. You've got good odds. Marinette's kind of edging you out – she's a known quantity and all – but five to one isn't bad. You've got to have those abs for something, right? Anyway, I've got twenty euros riding on this. Don't let me down."

He clapped his shoulder again bracingly and moved to join the rest of the spectators.

Marinette, meanwhile, was having a hissed argument with Alya, who was shaking her head patiently and whispering back. Adrien caught the words "Adrien", "chance" and "favour".

"All right!" Max shouted, clapping his hands together. "Betting's over. There are exactly eight minutes until break is over, so I suggest we commence. Over to our commentator."

He turned to Alix, like a newsreader, who didn't hesitate to step up to the table, clearing her throat loudly.

"Thanks, Max." She clapped her hands together, then flung her arm out in the most dramatic act of pointing Adrien had ever seen.

"On my left is our reigning champion: the Pink Punisher! The Furious Fashionista! The Pint-sized Princess of Pain! Marinette! Dupain! Cheeeeng!"

A cheer went up from all the assembled girls.

"And on my right is her challenger – "

"I never – !"

"The Model of Mayhem! The Beautiful Bruiser! The Washboard Wrecking-ball! Newcomer: Adrien! Aaaagreste!"

An even bigger cheer went up from the guys in the class.

"Yeah!"

"Come on, Adrien!"

"Do it for Kim! Avenge his honour!"

"Hey!"

He should refuse, really. He should just walk away. He is a gentleman, gentlemen do not arm wrestle ladies. Or arm wrestle at all. His father would have a fit. Not to mention, his superhero double life gave even his civilian self an unfair advantage.

And yet.

Everyone was cheering. For him. And it had nothing to do with his face.

Adrien planted his elbow on the table, flushing and trying to ignore the warming in his chest as the whole class cheered.

Marinette sighed and did the same, taking his hand in hers with a blush. Adrien swallowed and focused on keeping his face impassive, despite the tingling of his skin.

"I'm sorry about this, Adrien." She was looking at him almost pityingly, fully expecting him to lose.

There was something familiar about that expression. And, for whatever reason, it put him on his mettle. He felt her start with surprise as a Chat Noir grin slipped onto his face.

"You haven't won yet. It is on!"

He vaguely registered Nino crowing and Alya laughing at Marinette's shocked expression as Alix shouted "Begin!"

And suddenly his fist was being squeezed in a vice-like grip and his muscles were straining to keep his arm at a right angle.

Because, good Lord, was she strong.

Despite her earlier display, he thought he'd be able to defeat her easily. But her arm wasn't budging, though he had the satisfaction of seeing her eyes widen in surprise, then screw up in concentration as his didn't either. Was that the tip of her tongue poking out?

Cute.

But no, he reminded himself. Now was not the time. He had an arm wrestling match to win.

Unfortunately, it seemed to be a case of an unstoppable force meeting an immovable object. He just wasn't sure which was which.

As the seconds stretched into minutes with neither of them gaining any ground, their audience went wild. Alix was commentating rapidly, shouting excitedly and waving her hands. Through his haze of concentration, Adrien caught the odd "Unbelievable!", and "Amazing!" as his world narrowed to Marinette's fist.

He wanted to win. He really wanted to win. People were impressed with him. Adrien. They were cheering for him.

Chat could do this. I can do this.

"You'll tire eventually," he ground out.

Marinette snorted, her fingers crushing his punishingly. Really, it was quite refreshing, if painful, to see her engaging with him so directly.

"In your dreams," she hissed back.

Now, why did that sound familiar?

The Chat grin he'd manged to maintain the whole time widened. Lowering his voice so only she could hear, he whispered back.

"No, Princess. In yours."

That did it. He saw her face go slack with shock and took advantage of her distraction to slam her fist into the table.

"Yes!" He stood up, punching the air victoriously.

Nino was pounding him on the back and his classmates were rushing to congratulate him, screaming and jumping up and down jubilantly, as if he had just won an Olympic event. Everyone ignored Alya's indignant cries of "Cheating!"

Adrien grinned. Until his eye slid back to Marinette. She hadn't moved from her seat, but her face was darkening, like a thundercloud, as her eyes burned into his.

Suddenly, his mouth was dry.

Shit.

He had just outed himself as Chat Noir to a classmate. Just to win an arm wrestling match.

Shit.

He was in so much trouble.