I do not own Harry Potter or anything you recognize from the Harry Potter world.
Sirius snuck into his own dorm room, knowing that if he failed in this private mission, he would never hear the end of it. Seeing as it was only October, he was hoping to avoid that fate. Luckily, James was at Quidditch practice, Peter was in detention after being caught out after curfew on his way back from the kitchens, and Remus was in the library studying with Evans.
So, it was with this in mind, that the dark haired youth snuck into his best mate's trunk searching for Honeydukes chocolate bars.
He had no idea that Remus had forgotten a book he needed to return, and was thus on his way back up to the dorm room.
Just as Sirius located the last chocolate bar in the "secret" stash, Remus walked in and leaned against the door frame.
"Padfoot, what in Merlin's name are you doing?" He asked, shaking his head as he took in the form of one of his best mates kneeling at his trunk and holding aloft his last chocolate bar.
"Moony!" Yelping, Sirius fell back onto his bum, stuttering until he sent his most charming smile to the werewolf. "I was just going to put this out on your table for when you got back! That's all, mate!" He could instantly tell Remus didn't believe him. The look on his face said it all.
"Padfoot, that is my last chocolate bar and we don't have another Hogsmeade weekend until next week. You ate all of yours yesterday, while Wormtail and Prongs finished theirs last week. You were going to take it, weren't you?" There was no anger, just mild amusement at the predicament the first Black sorted into Gryffindor found himself in.
"No! Why would I take my best mate's last chocolate bar?" Sirius would deny this until his last breath, be was not going to admit to trying to steal Moony's chocolate, not with the full moon only a few days away.
Remus raise one eyebrow, used 'Petrificus Totalus' on the dark haired Gryffindor and took the chocolate bar. Grabbing his book, he waved at his friend as he left their dorm room, taking the chocolate with him for safe keeping.
.:':. ':.:' .:':.
The Marauders didn't let Sirius live it down, taunting him for trying to steal Remus' chocolate for a solid month before they finally found something new to do, mostly hexing Slytherins in the halls. Though when it came time for the next person to take the blame so the other three got off detention free, Sirius was the one to take it. With Professor Sprout of all Professors!
She had him fertilizing the green houses, which in turn made him reek for a week.
"See, Padfoot, this is what happens when you try stealing chocolate, you end up in the doghouse. Now, grab a blanket and go sleep in the common room, you stink!" With that, the other three boys threw dirty laundry at the fourth member of their group until he left, laughing all the while.