A/N: This may become part of another story I am working on, as a flashback, but for now I thought I'd post it as a snippet. Setting: Book 6, after Slughorn's Christmas party.
"I had a very nice time, Harry Potter," Luna said.
"Mmm, me too," Harry slurred as he walked Luna to Ravenclaw tower. He was pleasantly warm and buzzy. "What time is it?"
"Half past midnight," Luna replied, taking Harry's arm. "It's right around this corner," she said, leading him in the correct direction. "Are you going to be able to find your way back to Gryffindor tower?"
"Mmm…" Harry murmured. "I suppose so. It's somewhere that way," Harry gestured vaguely. Luna stopped in front of the Ravenclaw entrance, releasing his arm. "Night, Luna," Harry said, drifting back toward the main staircase. If he got that far, drunk or not, he was sure he'd be able to find his bed and collapse.
Slughorn's Christmas party had been interesting, to say the least. A bawdy game of Truth or Dare had Zabini dancing with Luna (if you could call what Luna was doing dancing), Hermione admitting that she had had a crush on Gilderoy Lockhart in her second year (what girl at Hogwarts hadn't?), and Harry being triple-dared to kiss Professor Snape. Snape of all people! Harry chugged half a bottle of Firewhiskey in preparation, only to find, much to his relief, that Snape had already left the party.
Harry started humming as he wove his way, a bit unsteadily, toward a main corridor. He misjudged a step and bumped into the wall. "Bugger me silly," he muttered, pushing off the cold stone. He let his fingers trail along the ragged surface, studying the flagstones beneath his feet, trying-and failing-to avoid stepping on any cracks. Still humming and watching his feet, he failed to notice the man who had come to a stop before him.
"Mr. Potter," a voice sneered.
Harry lifted his head and felt the world spin, toppling into the wizard before him. His face plastered against dark robes covering a hard chest, he inhaled the scent of starch and linen and mint. And then, realizing who he was leaning against, he giggled.
Forceful hands grasped his shoulders, setting him back on his feet. "Potter," Snape hissed, "what do you think…
Harry raised his eyes, a lopsided grin on his face. Triple dare, triple dare, truth avoided, triple snare. Staring at the man's mouth, Harry rose up on tiptoe, closed his eyes, and placed his lips against Snape's. They were warm and soft and surprisingly pliant for such an inflexible, harsh man. Intrigued, Harry began to move his lips on the unforgiving mouth, wondering what Snape would taste like. He slid his tongue forward, licking, sampling…
"Potter!" Snape shouted, shoving him away and holding him at arm's length. "What in Merlin's name do you think you are doing?"
"Kissing you," Harry said. And then he laughed. His blood was singing in his veins, his head was spinning, and this all seemed so very funny. "I kissed Professor Snape, I kissed Professor Snape," Harry sang in a sing-song voice.
Snape dropped his hands from the boy's shoulders and crossed his arms over his chest. "You are drunk, Potter."
"I am, aren't I?" Harry replied with wonder. "First time for everything," he said, raising a finger to touch his own lips, and then looking up at Snape, cocking his head. "Are you going to expel me?"
"I wish," Snape grumbled, grabbing Potter's arm and dragging him forward.
"Ow," Harry complained. "Let go."
"As amusing as it would be to watch you fall flat on your face, Potter, I would like to get some sleep this evening."
Harry was compelled to keep putting one foot in front of the other as he was ferried down the corridor.
"Gryffindor tower is this way," Snape said.
Harry felt himself being jerked sideways, stumbled, tried to right himself, and tumbled into Snape. Again.
"Potter…" Snape warned.
"Sorr…" Harry started to say as he righted himself. And then, he got the hiccups. "Sorry hiccup sir hiccup".
Snape groaned. "What did I do in a past life to deserve this?"
"Vampire hiccup" Harry said. "Or a troll hiccup". Harry chuckled. "A hiccup vampire hiccup troll!" Harry proclaimed. "Can you hiccup imagine?"
"Potter…"
"Ow hiccup," Harry complained at the renewed pressure on his arm, still chortling. "Or…"
"We are here," Snape announced, delivering him to the portrait of the Fat Lady. "I suggest you get some sleep."
"Alright, Professor," Harry said, and then hiccupped one last time. Harry leaned against the wall next to the portrait. "Professor?"
"What is it now, Potter?" Snape sighed.
"It was nice… kissing you," Harry murmured, starting to feel sleepy. "Felt nice," he concluded.
"Bed! Now!" Snape snapped.
"Yes, sir," Harry said, still smiling as he climbed through the portrait hole.
The next morning, as the rays of sunlight spilled through the dormitory and a headache pounded in his skull, Harry recalled bits and pieces of the walk back to Gryffindor tower with the utmost mortification. Had he really kissed Snape? Had he really told the man it had felt nice? Harry groaned and buried himself under his pillow. Snape was going to make his life hell for his.
And then another odd thought crossed his mind, one that made his face flame even hotter. True, Snape hadn't kissed him back, hadn't so much as moved a muscle under Harry's clumsy administrations. But, Snape also hadn't cursed him into next year or screamed at him for his impertinence. In fact, Snape hadn't punished him at all; he hadn't given him detention or even taken points. And that was not like Snape at all. Harry fell asleep wondering what it could mean, landing in dreams much more torrid than a chaste kiss, with the snide Potions Master playing the leading role.