Disclaimer: I do not own the Fairy Tail series or any of the characters.

Summary: Wendy is a bad girl. But who is corrupting who, here?

Bad Influence

"Do it!"

Wendy hovered over the unconscious body, weapon in hand, poised for vengeance. Good and evil were at war within her gentle soul, and the battle could go either way.

"You know you want to..."

Her tempter, grinning and urging her on in a gleeful whisper as he crouched beside her, was not making it any easier for her to decide to do the right thing.

"I... I can't..." she whimpered. She shifted uneasily as a wicked little corner of her usually soft heart made its presence known. Liar, it said. You could. You totally could.

"Come on, don't you want revenge?"

Wendy felt her expression harden. Oh yes, she certainly did want revenge. Definitely. Some crimes could not be forgiven. But could she really dispense this sort of justice?

"Wendy."

The sound of her name being uttered so gently shook her from her thoughts, and she looked up to lock eyes with Natsu. Natsu, who she admired so much. Natsu, who was the big brother she had never realized that she needed, until she met him. Natsu, who embodied everything good and noble that Fairy Tail was made of.

"Wendy, he ruined your cake," Natsu persuaded, looking as though the very idea was breaking his heart. "He ruined your cake on your birthday. Don't you think he deserves this?"

His expression was so earnest, and his face was so close, and maybe she thought of him mostly as a brother now, but she'd had a bit of a crush on him in the beginning, and it had never completely gone away. And he had no idea about the effect he could have on girls, which just made him even more adorable.

Her resistance crumbled. Who could withstand that sort of emotional manipulation?

She removed the cap from the permanent marker that she held in her hand, and started drawing on Gray's unconscious face.

Stupid, drunk ice mage. Why had everyone been drinking, anyway? It was her birthday, and she wasn't old enough to drink, so whose bright idea was it to crack open a few barrels? Cana's idea, probably. Wendy would have words with her later. And then the fighting had started, as usual, and Gray had blasted her cake off of the table with his ice magic while aiming for Gajeel. And he didn't even apologize, because by then he was too busy trying to freeze Elfman's feet to the guild hall floor.

Wendy had ducked and dodged as she scrambled about, desperately gathering up her presents to save them from being trampled underfoot. Then she had taken cover behind the bar, where she indulged in a magnificent sulk as she waited for the others to exhaust themselves.

Eventually, the worst offenders had all passed out, and the less intoxicated ones had staggered off towards their homes, apparently deciding that with no Wendy in sight, the party must be over. It was then that a surprisingly sober Natsu (well, mostly-sober) had appeared, easily picking up her scent from across the room once the commotion died down. He'd coaxed her from her hideaway with sympathy on his tongue and mischief in his eyes as he handed her a marker.

Which brought her to her present situation.

She started by giving the ice mage a monocle, a curly moustache, and an evil little goatee (to match his evil, cake-destroying personality). She carefully "fixed" his eyebrows, sketching some hairs in the middle to give him a lovely unibrow. Daringly, she drew two large circles high on his shirtless chest (adding some shading to create a more realistic three-dimensional effect), and wrote "I *heart* boobies!" in block letters across his stomach.

"Nice," Natsu admired, snickering. "He can't even complain, 'cause it's totally true."

"Roll him over," Wendy directed mercilessly. "I've run out of room."

As the finishing blow, she wrote, "My panties make me feel pretty!" across Gray's back, using the girliest writing she could muster. She knew that he would never be able to hide it; even Erza's threats couldn't get him to keep his clothes on for more than ten minutes at a time. Everyone would see it.

Such is the malice that lurks within the soul of even the kindest thirteen-year-old girl.

Natsu rolled on the floor with mirth, trying not to laugh too loudly, as Wendy added hearts and stars and flourishes to her artwork. Finally, she sat back on her heels, feeling purged.

"I think I'm done," she said, surveying her work.

"What's going on here?" thundered a stern voice.

They spun around and froze in terror. They were caught! Caught red-handed, by the absolute worst person they could possibly be caught by.

Erza was awake.

Erza, who Wendy admired as much as she admired Natsu. Erza, who was so kind and generous and protective. Erza, who had invited Wendy to join Fairy Tail in the first place! Wendy was disappointing one of her idols!

"Don't kill us!" squealed Natsu, cowering. Useless boy.

Erza glowered at him, and then turned her glare on Wendy, who quailed as she realized that she was still clutching the evidence.

"Explain," Erza ordered.

It took a moment for Wendy to remember how to speak. "He ruined my cake," she replied in a tiny, wobbly voice. "And he didn't say sorry."

This paltry excuse, as it turned out, was the best thing she could have said.

Erza continued to glare for a moment, and then lowered her head, hiding her eyes behind her hair. "I was looking forward to having a piece of Wendy's cake," she whispered as if speaking to herself, with that strange intensity she displayed at the oddest times. "I chose it especially for Wendy's birthday, knowing that Wendy is so fond of chocolate. But now..."

Erza's breath hissed out between her teeth. Her armoured fist clenched for a moment, trembling as the fight between good and evil that had warred within Wendy was kindled in her own heart.

The battle was short-lived. Erza took cake very seriously.

"You should dress him in panties," Erza declared abruptly, raising her head. "And then put his pants on him to keep it a surprise. When he wakes, he will naturally blame Natsu for all of this and want to fight. At that point, he will inevitably start to strip, displaying his humiliation for all to witness."

Wendy and Natsu stared in awe.

From nowhere, Erza produced a pair of frilly underwear, proffering them to Natsu.

"Did you just pull these from your exquip space?" Natsu asked. "They look like something Lucy would wear. Did you steal them from her?"

Erza ignored the question, cheeks slightly pink. "Take his underwear off and put those on him. Wendy, go and find his pants. They must be around here somewhere."

Wendy went to do as she was told, giggling as she heard Natsu's response to Erza's orders.

"Alright, but if he needs tucked in, you're doing it," Natsu said. "I'm not touching his junk!"

By the time Wendy found the discarded jeans, Erza and Natsu had finished their work. Wendy tried not to look too closely as she handed over the trousers; the panties didn't provide much room for "tucking in" anything.

Not that she hadn't seen it all before, of course. This was Gray, after all.

Natsu and Erza wrestled Gray into his pants, and then they all stood back to admire the full effect as Gray continued to snore, blissfully unaware. Erza nodded decisively, apparently satisfied.

"I will buy you a new cake, Wendy," she declared. "I will hide it until the fighting is over, and then we will enjoy it together. I will return shortly."

Erza strode away. Wendy couldn't help wondering where the armour mage planned to find a cake shop that was open at 2 a.m., but she supposed that any cake shop owner with a healthy sense of self-preservation would gladly open their doors when Erza came knocking, no matter what time it was.

"Did we just corrupt Erza?" Wendy asked, watching her go. "Or did she corrupt us?"

Natsu shrugged. "It's kinda hard to tell with her, sometimes."

Gray murmured in his sleep, oblivious to it all. They watched him for a bit.

"You're a good draw-er, Wendy," Natsu complimented. "I probably would have just drawn a dick on his forehead, since he is one."

Wendy felt her cheeks redden. "That's embarrassing," she squeaked, aghast. "I couldn't draw something like that!"

There was a pause.

"I can," Natsu announced slyly.

Wendy handed him the marker without the slightest hesitation. She could never do such a thing herself, but she had no qualms about giving someone else the means to do so.

"Maybe on his neck..." Natsu mused, uncapping the marker as a devilish grin lit up his face.

Wendy covered her mouth with both hands, trying not to giggle too loudly as she watched Natsu work. She couldn't wait for morning to come!

Best birthday EVER!

::Owari::

A/N: Come on, no girl can be all sweetness and light all the time, right?

I had this idea a few weeks ago, in the vaguest sense, but I was suddenly ambushed by all the details at once, and I had to get it all down on paper right away. This was originally intended to be part of my "Tell Me a Fairy Tail" collection, but as the word count kept creeping higher, I changed my mind and decided to let it stand alone.