"Err…Prongs?"

"Yep"

"What are you doing?" asked Sirius, striding over to where James was perched on the edge of a squashy armchair in front of the fire, his brow furrowed in concentration.

"What do you think I'm doing?" James snapped

Sirius raised an eyebrow, but James wasn't watching.

"That's not going to work you know", said Sirius, smirking.

"Shhh!" hissed James, "I need full concentration"

Sirius suppressed a snort, James, concentrating?

"Oh my god", James whispered, very carefully pulling back his hands, and then…"I actually did it!" James grinned. "This is the most skilful thing I have ever done", he said, sounding smug, "and I didn't even cheat with sticking charms."

On a dark wooden tray placed carefully on James' lap was an eight-story house of colourful cards; not just any cards, but exploding snap cards.

"I. Am. Amazing" said James excitedly, "an utter genius!"

Sirius stuffed his fist into his mouth to stop himself from laughing.

"What?" asked James, the smile fading from his face.

Sirius simply couldn't help it, it was too funny. He let out a roar of laughter that made several of the younger students sat at the tables behind them jump in alarm.

"What's so funny? James demanded hotly, "I can't see you doing any better!"

Sirius only shook his head, now rolling around on the carpet, tears of laughter streaming from his eyes.

James huffed and ignored Sirius, once again looking at his masterpiece in awe. God he was good.

Sirius' laughter was finally interrupted by Moony entering the common room, his arms laden with heavy looking spell books.

"What's up with him?" Remus asked

"Honestly, I have no idea", said James, staring weirdly at Sirius who now seemed to be struggling for air. "I showed him my card house, my exploding snap card house, and he just cracked up and started rolling around like a dog."

Remus looked momentarily confused, but as he looked from Sirius to James to the card house and back, a small smile came over his face.

"Well, I'll just leave you to it" said Remus. He carried his books over to the entrance to the boy's dormitories, face split into a wide smile almost as big as Sirius'.

James, who was getting thoroughly pissed off, resisted the urge to stamp his foot and instead opted for shouting at Sirius, "Sirius Black you will tell me right now what the hell is so funny or I swear to God I'm disowning you."

Sirius laughed harder, but sat up wiping his eyes, and choked out through his laughter "well…y-you've" Sirius howled with laughter again, "you've done it on a tray"

James didn't see what was so funny. "Well I wasn't going to do it in the fireplace was I?" he said, as though Sirius was a bit dim.

Sirius hiccupped through his laughter and then said in a rush, "and the tray is on your lap! You're going to have to move!"

James' mouth fell into a comical 'O' shape as he looked down at the house on top of his knee. The slightest nudge and the whole thing would blow up in his face.

As Sirius resumed his cackling on the floor, James suddenly realised with horror…

"…I really need the loo"