Chapter 2: Building Tension
Mami sat on the sofa, holding up a freshly printed sheet of music for her new song. "Hey, Ami! I made progress today," she said cheerfully, handing the paper to her sister.
"That's awesome, Mami!" Ami replied enthusiastically, her gaze grazing over the piece of music. However, she quickly noticed the flustered look on her sister's face as she noticed Ami's fuller chest, now noticeably rounder beneath her shirt, "What's the matter, is there something on my shirt?", Ami asked, trying to hide the knowing amusement in her voice, "Erm- N-nothing!", Mami stammered, promptly snapping her gaze away from Ami's chest, telling herself that it's just her imagination playing tricks on her.
To Ami, it was quite obvious that her sister was noticing the difference, this was exactly the reaction Ami was hoping to get. Feeling triumphant, Ami moved onto the next step of the plan. "Hey, wanna try some new flavored soda?" she asked casually, raising the bottle she was holding in her hand.
Mami hesitated, taking a deep breath before answering, "Sure, why not?"
Mami took a long, cold sip of the soda, feeling the refreshing fizziness of the liquid dance across her tongue. "Mm... that's good!", In the midst of taking another sip, Mami noticed that her chest started feeling unusually hot, along with a vague sort of tingle. She lowered the bottle from her lips and her eyes met her sister's face, wearing a knowing grin, then her cleavage, then back to her face.
It hit Mami, Ami's breasts did in fact grow, and that whatever happened, must now be happening to her own bust too. This revelation sent a thrilling wave of heat through her core. Her nipples, hardened by arousal, strained against her bra.
Feeling her cheeks burning, Mami looked down at her chest again, her heart racing in anticipation and fear. Her once modest B-cup chest had expanded to a plump C cup, swelling and rounding underneath her shirt. Her once flat stomach was now visibly bloated.
Mami's breath quickened, realizing that her body was changing right before her eyes, an excitement that Mami couldn't quite place surged thru her body.
Mami was speechless, her mind racing as she looked directly into Ami's smirking face that seemed to be relishing the shock and confusion written all over her features. Mami cupped her growing chest, still incredulous at the change.
"How- How did you do this?" she managed to ask, struggling to wrap her head around the reality.
Ami laughed softly, enjoying her sister's discombobulation. "That's a secret.",
Ami said seductively, her lips teasingly close to her sister's ear, Mami couldn't help but blush, she could feel tingles running from her ear down her spine, butterflies dancing in her belly, but she resisted, pushing Ami gently away, "Geez, sis, cut that out", she said.
Ami giggled
, her smile turning devilish. As if reading Mami's thoughts, she leaned forward slightly and whispered into her ear, "Don't worry, Sis, no one will ever find out what really happened here."
This only served to ignite the fire inside Mami even more. She found herself wanting to reciprocate these feelings.