I do not own Harry Potter, the Wizarding World, or any canon characters.

There is a polar opposite of veritaserum. It is called mendaserum, and it enhances your ability to lie.

-0-0-0-

"What did you just drink?"

Harry Potter turned and looked at his best friend, Hermione Granger. He swallowed, wiping his lips with his hand, smirking at her scowl. He knew it was due to him using his hand and not a handkerchief. "Just a little something for a headache," he said, slipping the potion vial into his pocket.

"Oh? Are you feeling sick?"

"Just a bit under the weather." He took a half step back when she reached out to touch his forehead. "I feel really hot," he explained when she looked at him with a hurt expression.

"Oh, well thank you I suppose." She looked at him closely. "Was it from Quidditch practice last night?"

"Yeah, probably not the best idea to practice in the rain."

"How come Ron was in the common room last night if there was practice?"

"A little solo practice. I've been fumbling the Snitch at practice lately so wanted to do some late night practice to work on my spotting and reflexes."

"That almost sounds plausible," she mused. "Are you lying to me?"

"I'm pretty good at it," Harry said with a smug expression. "But no, I'm not lying.

She hummed softly. "You should probably take it easy tonight then."

"Can't. Still have that Charms essay to do. I'm probably going to go to the library and work on it with Cho."

"Really? Why with Cho?"

He kept his face placid, noticing that it was her hurt expression. "She offered to help. She's pretty good at it. Aren't you busy with patrol tonight anyways?"

"Well, I can help you before and after..."

"I'd hate for you to do that."

She raised an eyebrow. "You'd hate it," she repeated, eyes watering.

He looked away so he would not see the tears building. "Yeah, I would. Sorry, it's the headache talking."

She nodded, turning away with bent shoulders and starting to sniffle. He hated doing what he was doing but it was necessary. With an awkward pat on her shoulder, he turned to flee.

"You must think I'm an idiot."

Harry felt himself being propelled into an empty classroom by a Banishing Charm. He was going to go for his own wand but seeing her blazing eyes made him raise his hands into the air. He watched as she closed the door behind them, locking it shut with a wave of her wand.

"Yeah, I do," he said defiantly.

She snorted. She leaned impossibly close to him.

"Hey, stay away," he said. He tried to back up but was stopped by the wall. He found him trapped between a wall made of cut rocks and Hermione's implacable will. He gulped.

She took a deep breath, breathing deeply through her nose. "Clotted cream," she said, recognizing the smell. "A bit early for afternoon tea isn't it?"

"No it isn't."

"You hate clotted cream."

"I love the stuff!"

With rolling eyes, she reached into his pocket, slapping his hand away when he tried to stop her. His face went bright red as her hands dipped into his pants pocket and she fished out the potions vial. She held it up to the light, looking at the dregs of the potion within. "Thistledown floating with pyrite in a tarnished silver solution. And your breath smells oversweet. Is this mendaserum?"

"What?! No! I don't even know what mendaserum is." He crossed his arms.

She sighed. "You can drop the act Harry."

"I don't need your permission to drop it. I can drop it whenever I want."

"Just so you know, mendaserum helps you lie but it doesn't actually trick people that know you."

He started to sweat. "You don't know me."

"You've been lying the entire time since you drank this."

"No I haven't!"

She reached out and touched his forehead. "You're not hot at all. And I know for a fact that there wasn't practice last night. The entire team was in the common room and your broom was in your dorm room. I've known you for years and you once told me you think clotted cream is vile and you rather honey and jam on your scones any day. And I know for a fact that Cho is terrible at Charms because Professor Flitwick accidentally told me that one day."

"You're not that smart," he said weakly.

She smiled. "You tell me the opposite often."

He sighed. "No I don't."

"You really can't stop lying right now, can you?" she said with wonder.

"I'm choosing to do this."

She looked at him. "Why are you avoiding me?"

"I'm...not avoiding you."

"Is it because of Ron?"

"He has nothing to do with this."

She leaned in closer. He tried to look anywhere else but at her. He tried not to notice how sweet she smelled: vanilla and cinnamon. He tried to ignore how soft her skin looked. How being this close to her made him feel warm.

"Harry, do you like me?"

He bit his lip. "N-no."

She smiled with triumph. "What would you do if I said I like you?"

"N-Nothing..."

"Then prove it," she whispered, her lips separated from his by a hair's width.

He leaned in and their lips met. He moaned softly at how impossibly soft her lips felt against his, how she tasted truly sweet and not the foul fake sweetness from the potion. Her hands came up to hold his head, her fingers laced into his messy hair. His hands came up to encircle her lower back and she melted into him.

They finally broke apart, their breathing heavy and almost in gasps.

"H-how'd you know?" he said finally.

"Your words are lies but you eyes never do," she said softly. "The potion doesn't affect your body language or expressions."

"Damn," he said. He ignored her huff at his language. "You know me too well."

"Hey, the potion wore off," she said with a smile.

"Yeah, I guess."

"Were you really so desperate to hide, you drank a potion to try and trick me?"

He nodded sheepishly.

"Good thing I'm stubborn and not an idiot." She gave him an arch look.

"I don't think you're an idiot," he confessed with a red face."

"And?"

"You're that smart."

"And?"

"I love it when you help me."

"...and?"

"I hate clotted cream."

She tapped her lips slowly and emphatically, giving him a very warm look.

His blush intensified but he finally smiled sincerely. "I like you," he whispered.

"Then prove it," she whispered back.