Before coming here, Ai had just come out of her evening shower. Instead of grabbing her usual pajamas, she'd grabbed the T-shirt he'd just peeled off before his shower—and pulled it on without hesitation.
The fabric was huge on her, draping over her frame like a nightgown, the hem brushing against her thighs and the sleeves swallowing her hands. But it was warm, soft… and smelled exactly like him.
His scent wrapped around her—faint sweat, shampoo, and that natural, comforting warmth that was just Onii-chan. She practically melted inside it.
Now she was curled against him in bed, nestled into his chest like a content kitten, the oversized shirt wrinkled and loose. Shin had an arm draped lazily around her, fingers resting on her hip. His other hand was propped behind his head, eyes half-closed.
"You smell so nice," Ai murmured, pressing her nose to his shirtless chest. "Even sweat smells good on you, Onii-chan…"
"You're such a little freak," he said fondly, brushing a hand through her still-damp hair.
"Mmhm," she hummed proudly. "Your freak."
Shin chuckled. "Why are you wearing that shirt anyway? Wasn't it supposed to go in the laundry?"
Ai looked up at him, eyes wide and teasing. "I was going to wash it… but it felt so warm. I couldn't resist."
He smirked. "You're seriously hopeless."
"I love smelling like you," she said, pressing herself tighter against him. "Feels like you're hugging me even when you're not."
"I'm literally hugging you right now."
"Exactly," she whispered, voice thick with attachment. "Now it's double."
Shin rolled his eyes, but his fingers tightened just a little on her side.
Then, Ai slowly shifted. She crawled up just enough to straddle his waist, settling her weight gently on his hips, and looked down at him with a mock-serious face.
Ai shifted slightly, rubbing her cheek against his chest like a sleepy cat. Then, without warning, she whispered, "Onii-chan…"
"Hm?" he mumbled, eyes still closed.
"You stole a kiss earlier," she said in a mock-serious tone. "Unforgivable."
A lazy smirk curled Shin's lips. "That so? Pretty sure you've stolen, like, a thousand from me."
"That's different," she huffed, lifting her head to pout at him. "I'm your little sister. You're supposed to just take it."
He cracked one eye open, amused. "That logic makes no sense."
"Shh," she said dramatically. "Don't question it."
Shin just smiled.
Ai huffed. "So, as your little sister, I have no choice… but to punish you."
Shin raised a brow, amused. "Punish me how?"
She leaned forward, her long hair falling around them like a curtain. Her hands rested gently on his chest, and with a mischievous glint in her eye, she let the shirt slide off one shoulder… then another… until the neckline slipped low and loose. Her chest—bare underneath—was suddenly, fully exposed to him in the dim light.
Shin's gaze didn't flinch. He looked—completely calm, casual—and smirked.
"Going all in tonight, huh?" he said, voice low and teasing.
Ai's face flushed, but she didn't look away. "Doesn't work if I don't commit."
"True. But you forget," he said, reaching up to gently cup her cheek, "I've known you since you were drooling on the couch watching animes."
"Shut up!" she giggled, swatting his hand. "Ruining the mood!"
"You're the one flashing me in my own shirt, Ai."
"It's your fault for making me feel like this," she whispered, leaning closer. "I want to be the only one you look at…"
She pressed a kiss to his cheek. Soft, slow, and lingering.
"Mwah."
He grinned and tilted his head, kissing her other cheek just as slowly. "Mwah."
She giggled and kissed his forehead, his temple, his jawline—everywhere except his lips. "Mwah… mwah… mwah…"
Then Shin glanced downward again and smirked, voice lazy and teasing:
"So, since I've seen 'em… can I touch, too?"
Ai's eyes widened. Her whole face flushed to the ears. "O-Onii-chan…!"
He laughed before she could respond, clearly joking. "Kidding, kidding. You're so easy to fluster."
But Ai, after a moment of stunned silence, muttered under her breath:
"…If it's you, I wouldn't mind."
Shin blinked—then gave her a warm, crooked smile and shook his head. "You're dangerous, Ai."
She huffed, burying her face in his neck again. "Only for you…"
Then she suddenly launched another flurry of kisses—cheeks, nose, forehead, even behind his ear.
"Mwah! Mwah! Mwahhh—!"
Shin laughed through it, catching her face between his hands and giving her cheeks a series of exaggerated kisses back. "Mwah—mwah—mwah—mwah!"
Their laughter filled the room like the soft hum of night crickets. Ai collapsed on top of him, resting her cheek against his chest, heart thudding but warm.
Shin's arms wrapped around her protectively, thumb brushing the small of her back.
"You really are something else," he murmured, kissing her temple.
Ai closed her eyes, voice soft and sleepy. "You're my everything, Onii-chan…"
Shin sighed, holding her tighter. "Yeah, yeah. You're my everything too."
---
Shin's arms were still wrapped lazily around Ai, the room dim and quiet, their laughter slowly fading into soft breaths and a peaceful rhythm. She was lying on top of him now, the oversized T-shirt draped over her petite frame like a blanket of warmth—except it did little to hide how close they really were.
She shifted slightly—just a little—but it was enough for Shin's eyes to narrow, a smirk tugging at his lips.
"…You really didn't think this through, did you?" he muttered casually, voice soft but clearly teasing.
Ai blinked up at him, puzzled. "Huh?"
He tilted his head with a mock innocent look. "You're sitting on me… and I can feel everything. You're not wearing your panties."
Ai's entire face lit up red, a jolt running through her spine as she immediately tried to sit up—but he held her in place with a gentle squeeze around her waist.
"Wait—wait, I didn't—!! I forgot!!" she blurted, face buried in both hands now. "I put your shirt on after the shower and—and I was going to—but I got distracted!"
"Distracted by my shirt?" he asked, grinning up at her. "You really are addicted to me."
She groaned into her palms. "Don't say it like that…"
Shin chuckled lowly, then leaned up slightly so his lips brushed her cheek again. "Mwah."
Ai whimpered into his neck, trying to hide the blush that had claimed every inch of her face.
"You're evil…"
He gave her another kiss, slow and teasing on her other cheek. "Mwah."
"You're not helping!"
"And you're not denying that you like it." His hands slid up her sides again, fingers tracing light shapes just under the hem of the shirt.
Then, his hand curved upward, gently cupping her chest again with a light squeeze. "Still not over how soft you are…"
"O-Onii-chaaan…!"
She whined, too embarrassed to move, but her hands gripped the fabric of his pillow tightly as she stayed right where she was, unable to meet his gaze.
He grinned even wider, pulling her down until her forehead rested against his. "You're so red, it's adorable."
"I hate you…" she mumbled into his mouth.
"No you don't."
"…Yeah. I don't."
He leaned in, kissing her cheek again—this time longer, softer, lingering. "Mwah."
She pressed one back onto his jaw. "Mwah."
He responded with a kiss near her temple. "Mwah."
And she gave one more to his neck, whispering softly, "…I only forget stuff like that when I feel too safe with you…"
Shin's teasing faded just a little, replaced with warmth behind his half-lidded eyes.
"I like that," he murmured. "Makes me feel needed."
"You are needed," she replied quietly, sinking into him again. "You're all I ever want…"
She whispered softly, "…Can we stay like this all night?"
He wrapped both arms around her securely, pressing one last kiss to her temple. "All night."
---
END OF CHAPTER : 6 : AI'S REVENGE!
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