The aroma of takeout Thai food filled the apartment as Leonard, Penny, and Sheldon settled in front of the television. Leonard, oblivious to the impending storm, was happily recounting a recent experiment while Penny scrolled through her phone, a sly smile playing on her lips. Sheldon, as usual, was meticulously arranging his chopsticks and making a mental note of the precise angle of the napkin dispenser.

"So, as I was saying," Leonard began, "The muon neutrino detector was…."

He was interrupted by the sudden appearance of Penny on the screen. Not just any Penny, but Penny with flawlessly styled hair, sparkling eyes, and a smile that could melt glaciers. She was holding a bottle of vibrant, flowery-scented shampoo, and as she spoke the words, "Shine brighter with 'Bloom'", a half-naked man, sculpted and glistening, appeared beside her. He wrapped an arm around her shoulders, and they both beamed at the camera. It was a brief, almost chaste, hug, but the implications were clear.

Leonard froze, his half-eaten spring roll suspended mid-air. His eyes widened as he processed the image. He turned to Penny, his voice a tight whisper.

"Penny... is that…?"

Penny, who had been watching him out of the corner of her eye, finally met his gaze, her smile faltering slightly.

"Surprise?" she squeaked, trying to make light of it.

Sheldon, oblivious to the undercurrent of tension, tilted his head.

"Fascinating. The commercial uses a technique known as 'sexual appeal' to entice consumers. An illogical method of marketing, given the vast majority of people possess hair, making the product necessary regardless of the presence of a shirtless man."

Leonard's cheeks flushed as he slammed his chopsticks down.

"You said it was a shampoo commercial, Penny!"

"It is!" Penny defended, her voice rising a little, "I just didn't… I mean, I forgot to mention, y'know, the...the guy." She gestured vaguely, unable to look him in the eye.

"You forgot to mention the half-naked man who was hugging you?! Come on, Penny, how can you just 'forget' that?" Leonard's voice was escalating. He felt a surge of anger, a cocktail of betrayal and jealousy bubbling inside him.

"It's not like he was, you know,naked, Leonard. He had a little, like, towel thing on," Penny insisted, making a hand gesture to try and define the scant piece of fabric.

"Oh, right, that makes it all okay," Leonard said, dripping with sarcasm. "A strategically placed towel changes everything! It's not the naked part that bothers me, Penny, it's thelyingpart!"

The argument escalated quickly to a full-blown shouting match, punctuated by the occasional clatter of Sheldon's chopsticks as he continued his meal, seemingly unfazed by the dramatic turn of events. They exchanged accusations, defenses, and justifications. Finally, when both were out of breath and emotional, Leonard ran a hand through his hair and sighed.

"It's not that I'm angry, Penny," he said, his voice now quiet and heavy. "I'm... disappointed. You lied to me and broke my trust."

Sheldon, who had been unusually quiet, reached for the remote and muted the television. He looked from Penny to Leonard, his brow furrowed in concentration.

"May I offer some advice?" He didn't wait for a reply. "This reminds me of the time Amy lied to me about being sick. I spanked her for it."

Leonard and Penny stared at him, completely dumbfounded. After a beat, Leonard asked.

"You didwhat?"

Ignoring Leonard's disbelief, Sheldon continued.

"She seemed to enjoy it, which, in retrospect, was a less than ideal outcome. I would advise, Leonard, if you insist on a similar disciplinary tactic, to make sure the spanking is significantly unpleasant, otherwise the desired results won't be achieved." With that, he rose, placed his chopsticks in their designated drawer, and retreated to his room, leaving a stunned silence behind.

Penny blinked, her jaw slack.

"Did… did he just…?"

But before she could finish the sentence, she noticed the slow, spreading grin on Leonard's face. It was a mischievous, slightly evil grin that sent a shiver of apprehension down her spine. She recognised that glint in his eye, and she knew what was coming. Panic and a strange sense of excitement fluttered in her chest.

"Oh no," she whispered, before turning and sprinting out of the apartment, a giggle escaping her lips as she did.

Leonard chased after her, his own laughter bubbling up. They burst through Penny's apartment door, with Leonard finally catching her by the arm. He gently pulled her towards her couch and, deftly, placed her over his knee.

"Now now, Penny, we can't have you lying to me," Leonard said, his voice playful, but with a stern edge. "I was very, very disappointed in you. And the correct course of action for untruthful behavior is…"

Penny chuckled as she kicked her legs half-heartedly, trying to appear annoyed while secretly thrilled by the situation.

"You wouldn't dare," she challenged, teasingly.

"Oh, I dare," Leonard responded with a smug smile.

He started lecturing her, his tone deliberately over-the-top. He told her about the importance of honesty, the sanctity of trust, and the egregious nature of hiding shirtless-hugging co-workers. Then, with a wink, he gave her a firm, but not particularly painful, spank.

Penny shrieked and giggled, kicking her legs again. Another spank landed, a little stingier this time, and she made a show of squirming. He continued for about thirty seconds, the spanks echoing in the small apartment. Finally, he stopped and moved his hand to rub her bottom.

"Do you apologize?"

"Okay, okay! I'm sorry!" Penny said, giggling.

Leonard helped her up, his smile still smug.
Penny immediately grabbed Leonard's hand and pulled him towards the bedroom.

"Bedroom, now," she said, her voice suddenly husky and playful.

"Why?" Leonard asked, a mixture of confusion and amusement on his face.

"Because," Penny grinned, "I think I enjoyed that spanking a little too much."

Leonard chuckled, a deep, satisfied sound, and followed her into the bedroom without another word.

After a good amount of fun, they were lying in each other's arms, the earlier tension completely gone. Penny turned to face Leonard, her expression serious.

"I am really sorry, Leonard. You were right, I should have told you. I hate that I lied to you."

Leonard kissed her forehead softly.

"It's okay, Penny. I get it. You probably thought I'd overreact, which I kinda did. And… I guess I was more jealous than mad."

Penny smiled and snuggled closer.

"I knew you'd be jealous, but not as jealous asthat."

They lay in comfortable silence for a few minutes, just enjoying each other's presence. Then, Leonard spoke up, his voice taking on a teasing note.

"Just so we are clear, the next time you lie to me, I'm breaking out the wooden spoon."

Penny laughed, burying her face in his chest.

"Oh yeah, threat me with a good time again, why don't you?" She met his eyes, her gaze sincere and loving. "Seriously though, there won't be a next time, I promise."

Leonard smiled, his heart full. He knew, deep down, that she meant it. And the idea of a future filled with playful spankings, while undeniably amusing, wasn't half bad either. He pulled her closer and they just existed, comfortably, in each other's arms.