Disclaimer: Don't own it, yo.
AU, set in seventh year.
To put it quite simple, Harry was having a lot of fun.
Ever since the beginning of the school year, and Voldemort's death, Dumbledore had had Order members following him around. Harry personally liked to refer to them as "Potter-sitters", but nonetheless, they were still there. It was the best entertainment imaginable when Harry could make Tonks trip over something and then disillusion himself and make a stumbling run for it, or manage to successfully outwit Professor McGonagall and run, cackling madly, past her and out onto the school grounds to jump in a pile of leaves. There was a lot of running involved, to say the least.
Harry had waited nearly five months to get this particular Potter-sitter. He had dwindled the stocks of Order members and snuck past them one-by-one until Dumbledore was left with no other option. Having nearly thoroughly exhausted his escape tactics, Harry planned something . . . special for this Potter-sitter.
Harry snickered into his mittens. He was currently staked out in a shadowy corner in the Entrance Hall, waiting for some sign of the new Potter-sitter. He couldn't wait to get into the snow outside.
He braced himself; this would be one tough mission. Cautiously, he stuck his tousled head out the door to the grounds. He smirked inwardly and prepared to make his escape. Little did the dark pair of eyes stealthily stationed behind a tree know, they had been spotted by one bonkers Boy-Who-Lived.
Laughing insanely and having a scarf dragged along in the air behind him, Harry made a mad dash down the steps and towards the Lake. He was one hundred percent aware of the figure attempting to follow him without being noticed, but Harry Potter hadn't defeated Voldemort for nothing. Using all the leg strength he had built up as a child running from Dudley, he stumbled along (unbelievably quickly), flailing his limbs and having the time of his life.
Arriving near the frozen Lake, Harry twirled around in the snow and plopped down, panting and smiling. A couple minutes later, he was faced with his Potter-sitter, scowling down at Harry's flushed and grinning face.
"I am not sorry to inform you that any efforts put forth by you will be futile."
Harry smirked. "We'll see about that, Professor."
And with that, Harry stood up and turned on his heel, once again giggling insanely and headed for a thick patch of trees near Hagrid's hut. Yes, there might be some trouble, but Harry was not completely incompetent. The only problem that he had once he reached the vicinity of the hut, was that his Potter-sitter seemed to have disappeared. No doubt used a Disillusionment Charm, Harry mused. Well, he had a plan for that. He let forth another giggle at the poor Professor's attempts.
Practically right on cue, his Potter-sitter appeared right beside him and grasped both his arms in a death-grip. Harry, acting on his plan, turned to face the now-visible person and screamed like Voldemort had returned.
Of course, this caught the Order Member off-guard, and Harry was promptly released, free to make his temporary escape to the Quidditch Pitch. He was once again cackling uncontrollably and flailing his limbs about. On the way to the Pitch, he grasped his scarf tight; he would need it for his last-resort plan. It wasn't last-resort because Harry didn't want to do it, merely because he figured it would have the biggest impact. This thought aided in his relentless cackling and running. He threw in a few giggles, too.
Making his way towards the Pitch, he reminisced about the time he had made it to the broom shed just quick enough to snag a broom and spend a whole afternoon being chased about by a determined Kingsley Shacklebolt. Good times, good times.
He was still giggling as he stopped dead in the middle of the field and made an about-face to await the inevitable appearance of his panting Potter-sitter.
Of course, about thirty seconds later his Professor could be seen looking very serious and stomping his way towards Harry, who was grinning like no tomorrow.
When the man was about twenty feet from Harry, the seventeen-year-old held up his hand and cried out, "Stop or face the consequences!"
His Potter-sitter did stop, more out of surprise than obedience. He had a confused and frustrated scowl on his face. "What, pray tell, would be these consequences?" He used air quotations on the exaggerated word and Harry had a brief thought that the man sounded very immature. This only caused Harry to falter his serious stance with a giggle. He then resumed the stance and said this, if you'll believe it, with a straight face.
"Come any closer, Snape, and I'll start stripping."
Snape's eyes widened and he was too shocked to even point out that Harry hadn't called him sir or Professor. Harry giggled at this. That made Snape a bit mad. "Dammit, stop giggling at me! Stop your foolishness this instant, and get your ungrateful Gryffindor arse back in the Castle, Potter!"
Snape took a step forward, despite Harry's warning. Harry, sticking true to his word and snickering inwardly, dropped his scarf.
You could say his Professor was surprised. "I won't repeat it again, stop your idiocy and get inside the Castle, you insolent—"
The man had subconsciously taken another step, and that led to Harry (with a straight face, his mouth might've been twitching at the corner if you looked hard enough) dropping his cloak. At the look on his Professor's face, Harry smirked rather evilly. "I'll do it, Professor," he warned, still smirking.
Snape schooled his features into his usual serious look. "I have no doubt that you'll do it, but I have a job to do, now just get—"
He really needed to stop taking subconscious steps. Harry's robes and mittens joined his cloak and scarf on the ground, leaving him in shoes, socks, trousers, and a Gryffindor-red sweater.
The older man steeled his determination and took another step, preparing to drag the Seventh-Year away before he could drop any more clothes, but no such luck; Harry's shoes were kicked off and the socks joined the pile too.
Desperate to stop him now, Snape kept walking despite his (he wouldn't admit it) nervousness.
Harry knew better, and could see the patches of color on his Professor's cheeks. It made the man rather attractive, he mused, before pulling the sweater over his head as Snape continued moving towards him. This basically left him in the middle of the Quidditch Pitch, wearing only trousers (and boxers), with Professor Snape. He entertained the thought of how weird this was before reaching for his belt buckle.
Snape gaped at him, then realized what he was doing and closed his mouth, and made a mad dash for the green-eyed menace. Since he had already come quite close to Harry, this ended in a heap of the two; one fully clothed and the other not-so-fully-clothed.
They rolled around for a few moments, Harry trying to get Snape off him and Snape trying to capture Harry. The clever and not completely sane Seventh Year set his Snape-tuned tactics in motion. AKA, while Snape paused (however briefly), Harry took advantage and attacked Snape's mouth vigorously with his own. You could say the older man was a bit shocked.
Snape, being rather stunned at that moment, unknowingly let go of Harry. The younger and slightly girly man giggled once, then took off away from the Pitch.
As Snape sat there on the ground, watching Potter flail across the snow cackling maniacally and only wearing trousers, the only thing he could think was, "Bugger. They weren't kidding about Potter being deranged. I wonder how I could get those trousers off him . . ."