"No, no, no! That eyeliner is way too good to be mine. Smudge it a bit."

Sirius sighed and turned back to the mirror, hands coming up to mess the eyeliner he had just applied. Once he was finished, he turned back at Lily while she looked him over. After every square centimeter of Sirius' person had been carefully scrutinized, she nodded and popped her gray contacts in.

"What about me?" She asked.

"Perfect. Just remember, keep your back straight, your mouth open and to invade everybody's personal space," Sirius said.

Lily raised her eyebrows.

"Did you just insult yourself, Black?" she asked, amused.

"Maybe," he replied, smirking. "Now lets go to breakfast."

Aside from the fact that that Lily and Sirius were wearing each other's skin, it was a normal day at Hogwarts. Of course, they weren't actually wearing each other's skin, as that would be creepy, but instead were simply using muggle devices to change their appearance, as Lily put it, for a prank.

Lily—dressed as Sirius—took his normal spot on the left side of James, swinging a casual arm around Remus's shoulders.

Sirius—dressed as Lily—sat down on James' right. It took all of his willpower not to burst out laughing when James kissed his on the cheek.

"Good morning," James said

"Mornin'" Sirius said back, reaching for the coffee and silently wondering how Lily even found that voice changing spell, let alone performed it so well. Out of the corner of his eye he saw Lily talking to Remus.

Breakfast was over soon enough and Sirius found himself tucked under James' arm on the way to Transfiguration. Once the Marauders sat in their usual line, Sirius immediately got out Lily's inkwell, parchment and quill.

"Hey, are you alright? You seem a little tense."

He looked over at James and saw concern in his hazel eyes. That's when he realized he was sitting up too straight to be Lily.

"Yeah, I'm fine," he replied, slouching down in his seat. This was completely foreign in Sirius' book, so he was only sure he was doing it right when the look on James' face turned to relief.

McGonagall came in, minutes after and Sirius bent over his desk and started to scribble furiously. It was mostly gibberish, but he made sure that his handwriting was as atrocious as Lily's was. He couldn't even read what he was writing, so he considered this effort a success.

The only flaw in that class was when Lily was called up to turn the needle into a quill and she did it perfectly.

"Well Mr. Black, it seems you certainly have improved. Keep up the good work," Professor McGonagall congratulated.

"Thanks McGee. You do know how much I love your class," Lily said back, realizing her mistake. McGonagall's lips thinned but she said nothing.

Class continued as usual except for Peter. More than once, Sirius had caught him staring at Lily, or sometimes even him with his brow furrowed. Well, Peter was never the most intelligent of them, so Sirius tried not to dwell on it. But there was something in his gut saying that maybe he should.

Sirius was jolted out of his thoughts when McGonagall's sharp voice rang out about the homework

"Ten inches on why the enunciation of the 'a' is important and what could happen without it. Not you though, Mr. Black. You have a foot about turning the needle into a quill in excess of the other assignment. Class dismissed."

Sirius really hoped Lily would take one for the team and do his paper for him. He watched Lily get up and pack away her things. As if she read his mind, when she came past him she whispered, "nope."

'Go figure,' he thought. 'This prank better be worth it.'

Potions was their last class of the day. Frankly, Lily was surprised nobody had figured what Sirius and she were doing yet, as they were doing an extremely bad job.

Take Lily, for example.

In potions they were doing partner work and Lily was already halfway across the room on her way to Marlene when she realized what she was doing. Then, of course, when she realized that she needed to pair up with Remus (Sirius and James weren't allowed to even work in the same row let alone table and Peter decided he would like to work with a Hufflepuff today) she completely forgot that Sirius was rubbish at potions.

Now, she was no Severus, but she was naturally good at everything magical, so when she actually did the potion correctly (according to the instructions) Remus nearly fell out of his chair.

"Wow," he said with an awestruck look on his face. "Nothing exploded. The potion is the right color. You- I just- wow."

'It's just a one time thing,' she thought. Out loud she said "Thanks for the complement," and kissed him on the cheek.

Remus dropped both his spoon and his jaw. To her ever growing horror (and later, amusement) so did James, actual Sirius, Peter and a handful of others (which may or may not have included Slughorn, but no one was sure as he wasn't holding a spoon and his mouth was alway open).

"Did he just kiss Lupin?"

"Merlins deformed left leg, he did!"

"Ha! I totally called it! Pay up Sean!"

"Ahem, Sirius? Can I have a word with you?" Actual Sirius called to the girl dressed as him. Lily nodded and followed him out of the room. Slughorn was too busy trying to calm the uproar to notice.

"What. The. BLOODY HELL. Was. That?" Sirius inquired, turning almost as red as the wig he was wearing.

'Is that really what I look like when I blush? Man, I've got to stop that,' Lily thought. That was when she started to laugh.

She laughed and laughed until her stomach hurt and tears were leaking out of her eyes. She laughed until her cheeks were sore and she fell on the ground. That only made her shrieks louder.

"Okay, I get it, haha very funny. Now, why did you make it look like I kissed Remus bloody Lupin?"

Lily tried so very hard to answer, but all that came out was a soft, wheezing cough.

Unbeknownst to them, the rest of the Marauders sat inside the classroom with their ears to the wood of the door listening like one of those Muggle television shows Lily liked to watch.

Even through the thick wood, they were able to hear a bit of what was going on. Lily was demanding something, Sirius was laughing and Lily spoke again. But this is what really got them.

"Now why did you..." The word fizzled out for a bit before coming clear again. "Kissed Remus..." And promptly decided to fizzle out again, but the three marauders caught (what they thought was) the gist of it.

Unfortunately, they did not catch 'the gist of it,' so James stormed out there for nothing.

Apparently, James thought that Lily had wanted to kiss Remus as she was freaking out over it, so now James was freaking out over it which meant Peter had to freak out about it too, though he had no clue what 'it' really was.

"Lily! Am I not enough for you? I mean, I can see where you're coming from, he is cute, in a bookish sort of way, but come on! Between us two, it's clearly a no brainier!" Remus cried out.

'Wait,' Lily thought. 'Remus?'

"What?" Lily and Sirius asked unanimously in a monotone. A long silence followed that single word. Sirius was the first to break that silence minutes later.

"Er, Remus? Has all of that solitary confinement in the library finally gotten to you?"

Lily noticed that James and Peter were wearing obviously fake smiles. Peter nudged Remus.

"Come on, James. Stay in character," the smaller boy mumbled out of the corner of his mouth, barely loud enough for Lily to hear.

"Okay, what's going on?" She asked, still in Sirius' voice. Later, she would wonder how the voice charm she put on Sirius and herself hadn't worn off yet, as she was way too confused to think of something like that now.

After her sudden outburst, three of the four marauders grew suspiciously large smiles, so large, that it must have hurt.

"Well," James started. "Funny story, actually." He then proceeded to tell Sirius and Lily that he wasn't actually James. He was Peter.

Remus then piped up and said that he wasn't actually Remus. He was James.

"Wait. So that means..." Lily trailed off and looked at Peter.

"Yup," he said, popping the P. "I'm Remus. But you two have something to say as well, don't you?"

For two whole seconds, there was a stunned silence. Of course, Lily had to break it by bursting out laughing again. While she was laughing, she reached a hand up to her left eye, grabbed her lower eyelid and managed to blink away contact lens without poking her eyeball. She did the same to her right before grabbing the black wig she had on and tugging that off. After her emerald eyes and auburn hair were visible again, she calmed down enough to look at the boys.

James and Peter blinked owlishly. Remus and Sirius just smirked, wanting to let the rest of their group to finally put two and two together.

"Waaaait," James- in Remus' body- said, more than asked. "Explain please."

"Merlin, Moony. I thought you were supposed to be the smart one," Sirius goaded with a grin replacing his earlier smirk.

"Firstly, I'm not Remus. I'm James. Secondly, I'm so obviously the smart one Padfoot. Get it together mate."

"Saw-ry, Princess. Anyway, Lily and I did the same exact thing you three did, only with more muggle appliances," Sirius explained slowly, like he was talking to a child.

Remus- in Peter's body- snapped his fingers.

"I knew it!" He exclaimed. "I knew it. I told you they were doing it too, but don't bother listening to me."

Peter looked at the boy in awe while James dug in his pocket for the money he owed his friend.

Each of the three boys currently had something running through their minds. Remus was still gloating, albeit silently, Peter was wondering what the odds were that they would do this on the same day. James, on the other hand, was the only one to voice his thoughts aloud.

"Evans, what the crap did you just pull from your eyes?"

Lily let out a short little laugh.

"They're called contact lenses. Lily explained to the clueless pureblood. Muggles put them into their eyes to change their color. Or, they wear them so the don't have to wear glasses." She paused. "Wait, if you guys didn't use muggle stuff, what spell did you use to change? I looked all over, but I couldn't find anything."

The Marauders- excluding Sirius- looked at each other in a 'duh' fashion.

"Polyjuice potion. What else?" Peter said.

Suddenly Sirius was laughing his normal, barking laugh. Soon everyone else was laughing with him even though they had no clue why. Lily especially was getting real sick of the cramps her laughter was giving her. But, this had been an incredibly long and confusing day and they were all tired.

"Hey guys," Sirius said in an alarmed voice once they had all calmed down.

"Yeah," Remus gasped.

"When's that potion going to wear off? It's been, like, six hours and I haven't seen any of you drink anything since breakfast."

The trio froze.

"Oh Merlin," James groaned. "Pete, tell me you got the potion right."

Peter mumbled something under his breath.

"What?"

"I'm not a hundred percent sure!"

If you were to ask most of the students attending Hogwarts in 1977 what the weirdest thing that happened there was, no one would even think of the two identical shrieks of "GODDAMNIT PETER!" That happened on that fateful day, nor would they think of the response, "SORRY, BUT YOU SHOULD KNOW BETTER THAN TO PUT ME IN CHARGE OF SOMETHING LIKE THIS," and the waves of uncontrollable laughter that happened on that fateful day and even continued into the next. But if you were to ask a certain five people, all you would get was glares and giggles.

EDIT: Holy crap, guys. This story was littered with typos and errors in general. I actually decided to read over this an man, I'm glad it wasn't in a public place, this was embarrassing, yo. Anyway, thanks!