Junior Aurors didn't make much. There was no way he would have been able to afford a flat by himself without asking his parents for money and he wouldn't do that unless he had too. He and Cormac had been friendly enough during their Hogwarts days though he was older than the Gryffindor. Cedric had been made younger man's mentor during the Auror academy and they have formed a close friendship. When Cedric had first started looking for a flat and had found one not too far from the Ministry, he had wanted to live alone. After seven years of living with roommates, he didn't want to start his adult life with another roommate.
When he realised that flats were expensive, Cedric went in search of someone to split the costs with. Cormac seemed like the obvious choice. The man had grown up much the same way Cedric had. A family that was high up in the Ministry, plenty of money and standing in the higher reaches of magical society.
Oh, how wrong he had been.
Growing up with a small army of house elves and a mother and father who spoiled you rotten led to a grown man who couldn't do even the simplest things for himself. Plates were left everywhere in the flat, beer bottles were never cleaned up. The smell coming from Cormacs room finally became so unbearable that Cedric had threatened to kick him out if he didn't clean it up. Cormac paid his half of the rent on time so there wasn't much Cedric could say to him.
They had lived together for almost two years by the time Cedric finally had enough. He had drawn the short straw and had a late-night patrol of Diagon Alley. He didn't get off shift until well after three in the morning and just wanted to go home and pass out in his bed. The moment he apparated to the designated spot just outside the flat, he could hear laughter and yells coming from the fifth floor. With a sigh, Cedric headed upstairs.
Opening the door, chaos was all around him. There were people he had never seen before everywhere. The nice hardwood floors were covered in broken crisps, beer bottles, and clothing. Pillows were ripped open, photographs on the walls were either crooked or knocked off the wall completely. As soon as he shut the door, a girl, he didn't know who threw her arms around him.
"Great party!" she slurred before placing a sloppy kiss on Cedric's cheek and stumbling away.
Cursing under his breath, Cedric went in search of Cormac to punch the prat in the face. Finally finding the idiot holding court in the kitchen, he was too tired to even care. Cedric decided that revenge was best served cold and stalked off towards his bedroom.
It was three days before Cedric was able to put his plan into motion. He knew Cormac had worked the night shift at the Alley and waited until he had gotten home and was in a deep sleep. Sneaking into Cormacs room, he placed Weasleys Wildfire Whizbangs all around the room, just before he quietly crept from the room, he tossed four decoy detonators on top of the bed and a handful of Peruvian instant darkness powder into the air and slammed the door shut behind him.
Cedric doubled over with silent laughter as he heard Cormacs girlish screams as the Whizbangs and decoys went off all at once. Walking into the kitchen, he poured himself a cup of coffee and sat down at the table, basking in the sounds of his revenge. It was ten minutes later when the bangs stopped and Cormac finally stumbled out of his room and stomped into the kitchen.
"What the hell was that, Diggory?" Cormac demanded, his hair was singed and ash-covered his face and arms.
Hiding his smirk behind his cup of coffee, "Well, sounds like someone woke up on the wrong side of the bed this morning."