Her breasts swelled with an unexpected force each beat of her heart amplifying the change 
The world around her blurred a dizzying rush of sensation as her new curves took shape 
A mischievous grin played on Chara's lips witnessing the incredible expansion 
Frisk's transformation continued her body growing more pronounced with every passing moment 
Undyne approached her gaze fixed on Frisk's newfound size a mix of surprise and arousal in her eyes 
The sheer scale of Frisk's expansion was breathtaking a testament to the magic at play 
Chara watched her own desire sparked by Frisk's voluptuous figure 
The sheer weight of her enlarged chest made Frisk lean back a captivating display of her enhanced physicality 
Undyne's admiration for Frisk's curves was clear a deep appreciation for such magnificent proportions 
Frisk felt a surge of confidence her enormous chest a symbol of her sexual awakening 
A daring pose from Frisk highlighting her newly prominent features 
The intensity of their encounter grew Frisk and Chara locked in a sensual embrace 
Their passion was palpable a raw intensity that promised deep satisfaction 
Frisk's voluminous curves were undeniable a testament to her ultimate transformation 
Her body's fullness was a sight to behold every inch radiating arousal 
Undyne's bare chest revealed a powerful figure matching Frisk's own 
Frisk's enlarged chest dominated the scene a truly awe-inspiring sight 
The full glory of Frisk's sensual transformation captured in a moment of pure desire 
A final alluring shot of Frisk and Chara their forms intertwined their passion burning bright 