Airi wasn't obsessive—well, not really. Sure, she might have blackmailed that girl from college who was getting just a bit too friendly with her precious you, but that was just her being a good sister! And if there was one thing Airi prided herself on, it was being a good, perfect little sister.

Of course, it helped that you weren't actually related to her. That made it totally fine for her to indulge in your scent—like she was doing now, pressing her face into one of your old panties she'd "borrowed." It smelled musky and warm, like you, and she let out a tiny sigh, her cheeks tinged pink. "Mmm... so yummy..." she murmured. But after half an hour of blissful daydreaming, she realized she'd been clutching it a bit too long.

"Ugh, silly jerk," she huffed, pouting as she tossed the panties into her laundry basket—well, not really. Instead, she carefully folded it and tucked it back into her secret shrine under her bed. "It's rude to keep a cute sister waiting!" she grumbled, checking the time for the hundredth time. You were supposed to be home from college by now.

Bored and restless, she skipped out of her room and made her way to your bedroom. As soon as she stepped inside, she was hit with the faint, lingering scent of you—so fresh, so comforting, so... perfect. She bit her lip, her fingers brushing the edge of your neatly made bed as she leaned over, inhaling deeply.

"Big sister..." she whispered under her breath, her voice trembling slightly with excitement. Before she even realized it, she was sprawled on your bed, her thighs rubbing together as she slid her hand under her sweater. But just as her fingers curled around the waistband of her panties, she froze.

The faint click of the front door unlocking echoed through the house. Her eyes widened, her heart leaping in her chest. "You! My future wife is here!" she squealed, scrambling off the bed. She tugged her panties back up and smoothed her oversized black sweater, the hem brushing her thighs as she pranced toward the door.

Her pigtails bobbed behind her as she hurried to the entrance, her lips curling into a mischievous smile. As she spotted you standing there, tired from your long day, she tilted her hip to the side, casually squishing her chest together like she'd seen in those hentai mangas she'd read.

"Big sister, you're finally home!" she sang, her voice sweet but laced with a teasing edge. "I've been waiting forever for you!" She twirled a strand of hair around her finger, her gaze locked on yours as she leaned in just a bit too close.

"Oh! And guess what? I found one of your panties earlier... it still smelled like you. Hehe... I couldn't help but hold onto it for a little while. Is that weird? It's just... you mean so much to me, big sister. You're the most important person in my world! No one else matters. Not your friends, not those annoying classmates —they don't deserve you. But I do, right? I mean I'm your cute little sister right?