A/N: Not my greatest work but I thought I'd put it out there XD

Disclaimer: J.K. Rowling created this wonderful world that I love to fantasise and write about. She owns all rights!

Unknown Desires

"Good Morning class," Professor Slughorn said as he walked to his desk and placed his heavy looking briefcase down. He turned and his great bushy moustache curved above his small smile as he greeted the class. "Now then, books out, scales and potion kits too. Come on, chop-chop."

"Do you think he gets food stuck in that thing?" James laughed as he imitated the infamous moustache with his finger.

Sirius sniggered causing the Professor to turn glare at him.

"Right, settle down, please. As you can see I have brewed a few potions for you to have a look at." His large, velvet swathed arm indicated three heavy brass cauldrons, each holding a different potion. "Now then, who can tell me what this one is?"

Sirius turned to his left to see Lily's hand shoot straight up in the air. She was so predictable. Professor ignored Lily and turned his attention back to Sirius.

"Mr Black. Can you tell us what this potion is?" He asked, pointing to the first cauldron which held a potion that was as clear and as smooth as glass.

"I don't know," Sirius replied quietly.

"Hmmm. I would've expected you to know this particular potion m' boy. It's an easy one, this. Caused quite the bit of trouble lately. Ministry secrets exposed and the like." Slughorn waited a moment before finally turning his attention to someone else. "Mr Lupin. Can you tell us?"

Sirius heard Moony let out a small sigh before turning to him with an apologetic look on his face.

"Its Veritaserum, sir. Recognisable by its characteristic colourless and odourless state."

"Yes, very good. Now, how about this one?"

"Strengthening Solution," Lily shouted out before turning bright red with embarrassment.

"Yes well done, Miss Evans. Of course, you recognised its jade green hue and earthy scent?" Lily beamed and nodded, positively pleased with herself.

"And finally this one," Slughorn pointed to a dark violet potion in the last, brass cauldron.

It emitted the most intoxicating scent. Flowery but not overly powerful Once again Lily's hand shot up.

Slughorn looked at Sirius but seemed to think better of it. "Yes, Miss Evans?"

"That is Desiridum, sir."

"Well done, Lily. Very good. How did you know?"

"From its deep violet colour and distinct floral smell. Magnolia, Freesia and Lillies, I think." She said blushing slightly.

"My gosh, what a nose you have, m' girl. Absolutely correct. Ten points to Gryffindor. You know the effects of the potion, I assume?"

"It forces the drinker to reveal their desires," Lily replied meekly.

"Yes, but it is much more than that. It was developed by the ministry some years back as an aid to criminal trials. The thinking behind it was simple, those who had tried to plead that their criminal activity was done under the imperious curse would drink this, and their true nature was revealed. It worked to a degree, but in time the full effects were realised. Those who had trialled the potion started to display strange behaviour. They were consumed by desire and eventually driven to insanity. I show you this potion not to scare you but to warn you. The Ministry reports a rising trend in the illegal trade of Desiridum, and I for one, think you should not what to be on the look out for."

"But how can desire drive you insane, sir?" A Slytherin boy called out.

"Imagine wanting something so much that you lie for it, steal for it, kill for it, but even then you couldn't have it. Of course, everybody's desires are different, but nobody can withstand that kind of wanting for long." The potions master paused dramatically and glanced around the room, finally settling on the chair next to Sirius. James blushed, probably caught out thinking about Lily. "Mr Potter, what is it that you desire?"

"Erm..." James stuttered. "To see Gryffindor win the Quidditch Cup." He gave the professor a small smile.

"Ho ho, yes, of course, Potter. Very good but you really think it's possible?" His enormous belly shook as he laughed. "And how about you, Black? What is it that you desire?"

"I don't know, Chocolate," Sirius replied almost questioningly.

"Oh, the childish folly of youth. As you get older you will realise there is more to life than a simple sweet, Sirius." The professor chuckled.

What, like crystallised pineapple, Sirius wanted to bark back but he swallowed his thoughts. He could not afford any more trouble right now. "And I want to see Slytherin crushed," he added with half-hearted defiance.

"Hmm. Well then, on with today's lesson. Open your books to page forty-seven, Draught of Peace. Thoroughly read the instructions before you begin." Slughorn said dismissing him.

Sirius could barely concentrate on the textbook: his skin felt as if it were burning from Slughorns taunts. He could be such a condescending prick sometimes. He seemed to take great delight in torturing Sirius during class. Sirius wouldn't usually take his jibes to heart but today the man got to him. Trying to focus on what he was supposed to be doing, Sirius lit a fire under his cauldron, then started ferociously chopping ingredients.

"Err Padfoot...Padfoot...Sirius!"

James pulled on his sleeve, hard. "What?" Sirius snapped.

"What?" Sirius snapped.

"Your cauldron's on fire," James pointed to his cauldron, which was indeed engulfed in flames.

"Shit!" Sirius tried to fan the flames out but this only made them worse. So instead he furiously tried to blow them out. James and Remus tried to fan the flames with their textbooks books, but the fire still grew.

"My, my what is going on over here?" With a flick of his wand, Slughorn put out the fire and with another, vanished the contents of Sirius cauldron. "Pay attention to what you are doing, boy." his voice bellowed throughout the room."You receive a zero for your efforts today, Mr Black. This was very sloppy work indeed".

Sirius stared down at the empty space on his desk just waiting for the class to end. Slughorn walked around the room inspecting everyone's potions declaring most of them "Very good," there were even a few, "Perfects."

By the end of the lesson, Sirius was fuming. He threw his book and potion making kit into his bag and stormed out of the class without waiting for James, Remus and Peter. He carried on straight down to The Great Hall for lunch.

The house tables were full of delicious food; pies, potatoes and veg, sandwiches, various meats and cheeses, and pastries. Sirius sat down and loaded his plate. As he tucked into a steak pie, James came bombing down the aisle and sat dead opposite him.

"Alright mate," he asked.

"Hmm," Sirius replied with a mouth full of pastry.

James picked at a sandwich as they ate in an awkward silence.

"That thing with Slughorn really bothered you didn't it?"

"He just pisses me off sometimes" he admitted, grudgingly.

"I know. Listen, there's something I want to show you... and I... I think after that lesson you will want to see it... now," James ran his hand through his hair several times as he stuttered.

Sirius was intrigued. What had made his friend so nervous? James was usually so confident and cool, Sirius found it quite funny to see him like this.

"Okay," Sirius replied warily.

James broke out in a huge grin and Sirius couldn't help but return it.

"Cool, follow me," James beckoned as he rose from his seat and hastily walked out of the hall. Sirius ran after him with a mouth still full of food. He found it a little hard to keep up as he dodged students, all going in opposite directions.

They walked through the many, maze-like corridors until James finally came to a stop at an old, disused classroom. Inside most of the furniture had been covered by heavy cloth sheets, protecting it from the massive cobwebs that hung from the ceiling. Sirius looked at James in disgust. He was expecting an adventure, something fun, but this was a dirty old classroom. James grinned, urging Sirius into the room.

Sirius shrugged his shoulders and followed his friend as he lead him the centre of the room. James stop and pulled Sirius to face a large covered... thing. Sirius frowed but James was not disconcerted. He tugged at the covering to reveal a large mirror. James bit his lip as he waited.

"If you're trying to boost my confidence by making me take a look at my devilishly good looks, you didn't need to make me walk the length and breadth of the castle to do so. We have mirrors in the common room,"

James laughed softly, "Ahh but this is a special mirror. This is the Mirror of Erised and it doesn't show your reflection, it shows your hearts true desire. I thought after today's potions lesson, you might appreciate seeing it"

"Oh," Sirius mutter as he moved towards it. "So what do I do?"

"Just look into it," James replied as he walked out of the room.

Sirius stared at his reflection but nothing seemed to happen for a while.

He jumped back and gasped as James appeared at his reflection's side. The shock quickly subsided and Sirius watched the scene. James's arm was draped casually over his shoulders, they seemed to be laughing and joking together.

Sirius laughed to himself. If this was his true desire, he was set for life already. He chuckled when James pulled his reflection into a friendly embrace but his face slowly reflected his horror as he continued watching. James's hold on Sirius became firmer, more intense. James's fingers began to caress his back before softly cradling his neck and leaning in for a kiss.

"What the fuck" Sirius shouted out. Is this some kind of a joke, James? Cause it's a strange one."

Sirius shook his head in disbelief. He could not prevent the scene he had just witnessed from replaying over and over again.

It startled him that he was not more appalled at watching himself kiss another man. It actually felt as natural as kissing a girl. More so actually, Sirius had always found girls so awkward and difficult. He didn't really enjoy their company.

"Shit," Sirius muttered. Because he didn't mind watching James kiss him...Did that mean he was in love with his best friend? His head was spinning.

"You saw it too, didn't you?" James crept up behind him and whispered in his ear.

James turned Sirius around to face him but Sirius avoids his gaze.

"Saw what?" Sirius replies meekly, almost afraid of the answer.

"Us," James whispered.