AN: I don't own the characters just the idea for the fanfic, this is dedicated to Vamprincess38 hope you enjoy! Boy on boy no like no read easy enough, oh and implied sexual themes.

The six year students were dancing and having fun in a dungeon based Halloween party; the students were permitted to separate by years. Sixth years were in the dungeons, seventh years chose the astronomy tower. Fifth and fourth years compromised for the Great Hall, first and second and third had also group together to have an outdoor party in the Quittditch Pitch. The Professors had split two were year. Professor Snape and Professor Slughorn took the dungeon sixth years since they both knew the dungeons quite well.

The dungeon party was spread through what looked like an old wine cellar part with massive archways separating six different areas. The students had made one the buffet and eating area, at the other end was the dance floor, two were for sitting and another had a sort of mirror maze, the last was an area with tricks all up for grab and a gift from the Weasley twins. Slughorn took his time wandering around happily interacting with the students while Snape seemed to lurk around in the shadows.

One student was also hiding in the shadows and it was more because of Slughorn than anything else, Snape blinked curiously at the teenager who wore tight black pants and a black shirt which was ripped some as if having been attacked and the cat ears on the famous messy black head of Harry Potter. The boy looked oddly innocent with the cat ears het dark in the ripped clothing, it was almost sexual. The other two thirds of the golden trio had come as humanoid creatures as well. Hermione Granger was a mouse in a swimsuit sort of get up, thigh high boots and a mouse tail and ears on her head. Ron Weasley was what appeared to be a blood hound with floppy ears and a tail in what looked like footy pajamas.

"Miss Granger have you seen Mr. Potter anywhere?" Slughorn asked and Harry stepped further into the shadows not wanting to be dragged into an in depth conversation with the Professor who always seemed to make small comparisons to how Harry was like his parents or the Dark Lord.

"He said something about dancing," Hermione said and the man smiled and ran off towards the dancing section of the party, "Here kitty kitty."

Harry drifted deeper still and she seemed to blink before having a mild panic attack and grabbing Ron's arm, "Mione what is it?" Ron asked before she whispered in his ear, "How does he keep slipping away he's wearing a bloody bell!" and they left as well to go searching for their friend thinking he possibly went to the bathroom or for food.

Chuckling softly Harry let go of the bell around his throat and tapped it so it jingled just a little, "Idiots, why are all my friends idiots," he kept to the shadows as he watched everyone else having the time of their lives. He noticed the Professor following and blinked before turning to look at him with a tilted head, "Hello Professor Snape enjoying the party?"

"You're in a devious mood tonight," Severus said crossing his arms, "What are you plotting?"

"Oh nothing what so ever," Harry said cheekily it was almost as if his costume gave him a new level of confidence, especially since his glasses were gone and his eyes had been charmed to see like a cat meaning his night vision was excellent, "I've decided not to play any games what so ever," his charmed tail swished behind him some and he smiled lightly.

"Why would I believe…" yet Severus's eyes trailed off as he saw a collar around the teens throat, black with silver lilies and serpents twining around the fabric and small silver bell, "Is that a collar?"

"Yes, they insisted I wear something that makes noise so they can make sure I don't wander off and get into trouble," Harry said before walking off, he was headed for Draco Malfoy who was fooling around in a darkened corner with Pansy Parkinson. The Professor followed him still, slipping over he tilted his head allowing the bell to signal his arrival at their sides.

"Dray did you hear that?" pansy asked before seeing Harry quite close to them she blinked at him.

"Pansy it's probably Goyle's elf costume," Draco said as he nipped at her neck.

Harry bent down and whispered, "Not even close," and Draco glanced at him, "Boo," and the blond and Pansy jumped apart shocked that they had not heard him approach, "Heh that was fun," with a wave to them he drifted off into the shadows again his tail swishing some as he seemed to melt into the darkness.

"Holy hell Potter can be scary sometimes," Draco said before smirking, "At least it wasn't a Professor."

"I'm here as well," Severus said and they paled even more, "I catch you again and I'll be forced to take points," and the two nodded and ran off. Looking for the sneaky kitten he saw that black tail as it vanished into the hallways, smirking now that he had an excuse to take points he followed yet blinked in surprise Harry was nowhere to be seen.

A jingle made him turn and see that tail vanish around a corner and he headed that way, another jingle had him turning around and Harry vanished into a room. Walking in he realized this was a giant game to the teenager, he had to be sneakier then the brat. Yet it took him almost an hour of following that damnable jingle which lead him all over the place which actually lead to him handing out a handful of detentions since Harry seemed to be leading him to teenagers who were out breaking the rules.

Yet he found the teen sitting on his desk in the classroom playing with an empty vial as if a kitten playing with string, he froze as he noticed the teens body was stretched across the desk playing with the vial that daman tail flicking back and forth and he heard two whimpers come from the corner. Turning his head he saw two fourth year Gryffindor students, "Detention both of you Saturday seven!" and they nodded before glancing at Harry, "Get out," he told the students who fled.

The vial dropped to the floor and Harry leaned just a bit further so he could reach it and thus giving the man a perfect view of his body, hearing him approach he glanced at him and smiled some, "Hello."

"You're on my desk," Severus said eyes narrowed some, he was ignoring the tightening in his stomach as he noticed how delightfully sinful the teen looked laid out on the desk.

"It would appear so," Harry said before turning back to the vial he had tipped over off the desk, "Except this is not your classroom anymore Professor," and the teen dropped and slipped away before he could grab him, "So technically I would have been on your old desk."

"Technicality," Severus said watching the teen practically sway as he approached him, when he was about three feet away Harry ducked to the side and seemed to vanish again only the jingle let him know the teen was moving again. Following he was lead up and out of the dungeons, and he paused outside his office door which was cracked open and a jingle from inside let him know the teen was in there, "You realize I can give you so many detentions for this," he said as he watched Harry settled on the edge of his desk.

"I am aware of that," Harry said cheekily, before his tail flicked a couple times, "Do you know how hard it is to grow a tail?" getting a small shake as the man approached him he tilted his head allowing the bell to jingle once, "Took me about three hours since I connected it to my nervous system."

"So this is actually part of you?" Severus asked getting a nod he focused on the tail some, "Hmm, ten points to Gryffindor for human transfiguration."

"Thank you Professor," Harry said before the tail wrapped around his waist like a belt.

"And a month worth of detentions for sneaking away from the party, breaking into a classroom and my office," Severus said which got Harry to tilt his head the other way making that jingle go off again.

"Professor," Harry said calmly, "Why have you followed me all evening?" he had been leading him around for about an hour and a half.

"I just played the game," Severus said knowing this had been a giant game of cat and mouse; he was not sure which one he was at the moment since the teen was literally part cat at the moment.

"Good, you won," Harry said and grabbed the man's shirt with his sharp nailed hand and pulled him close connecting their lips in a heated kiss, feeling a hand pull him closer and another on the base of his neck holding him in place. A low purr like sound left him as the hand which had been on his lower back went to stroking his tail and he just seemed even more determined to taste this man.

Breaking for air he practically growled out, "You're playing with fire," he was warning the teen that if they continued he would not be able to stop himself.

"Not yet," Harry murmured kissing the man again as a hand drifted down and he earned a moan for his efforts, when they broke for air again he practically panted, "Now I'm playing with fire," and squeaked as he was pinned flat to the desk and knew his efforts had been worth it.

~Lemon can be found on Archive of Our Own story named same thing, authors name is the same, sorry it took so long to get out guys~

After calming down and finding their clothes Harry blinked at his shirt which was a bit more ripped then it had been before, "Good thing I thought that one through," and pulled the shirt on before feeling a deliciously hard body against his back and a kiss pressed to his throat right above the collar, "Mm."

"Wear this collar to class on Monday," Severus said as he reached up to brush a finger against the bell getting a jingle, "Happy Halloween kitten," he had never really liked cats before but now he had a special place in his heart for one very special kitten.

"Happy Halloween," Harry answered before glancing back at the man he had wanted to find a way to get this man for so long and after about a year of planning he had finally gotten the dungeon bat to come out and play with his inner kitty cat.