HLWN CSTM (Absorption, Inanimate TF, Expansion, RWBY)

Laughter rang outside the bathroom as Ruby studied herself in the mirror. Sighing, she raised her hands and traced the curves of the all-too-large vampire costume failing to grip her slender figure. Even the corset was too loose. Even the corset.

As she crumpled in despair, someone knocked at the door. “Ruby, are you okay in there?” came her sister’s voice. “You’ve been in there for a while.” 

“It’s fine,” said Ruby, wiping a little tear out of her eye. “It’s just… I think I might need to try a different costume. What had she been thinking, buying something like this? She should have known she didn’t have the curves to fill it. 

“A different costume?” asked Yang. “What’s the matter with that one?” 

“Don’t make me say it,” said Ruby, hugging herself. She’d always been jealous of Yang’s assets, and the last thing she wanted was for her sister to be aware of it.

“Make you say–Oh. Yang was silent for a few seconds. “Okay, I think I know what your problem is, Tuesday. Come on, come out here and let me help you.” 

Ruby shuddered. She didn’t know what Yang had in mind (stuffing pillows down her top, maybe?) but she couldn’t imagine it would be much help. 

Unlocking the bathroom door, she stepped outside, her costume hanging limp, and frowned to find Yang standing there with a vial of pink Dust in her hands, shaking it mischievously. “What’s that?” she asked. 

“Absorption Dust,” said Yang, with a playful smirk. “This’ll fill you out, I guarantee it.” 

Ruby blushed. “It will?” 

“Hell yeah. We just need to find some volunteers…” 

*

“Absolutely not!” cried Weiss. “I’ve been waiting all year for a chance to wear my Ice Queen costume, and I’m not going to miss it!” 

Ruby and Yang looked Weiss up and down. Her ‘ice queen’ costume was barely distinct from her normal clothes. 

“Aw, come on, don’t be such a spoilsport,” said Yang. “What about you, Blake? You up to enhancing Ruby’s figure?” 

Blake hid her face with her book and blushed. “I–I’m sorry, I’m not sure I want to get quite so close to her.” 

“Aw, come on!” said Yang, throwing up her arms. “It’s Halloween! Have some Christmas spirit, or whatever.” She huffed. “Fine, well, if you two won’t do it, I guess I’ll have to fill her out all by myself.” 

Ruby blushed. “A-all by yourself?” 

“Yeah,” said Yang, popping the cork of the Dust vial. “Hold still, Rubes. This won’t take a second.” She tipped a few pink sparkles onto her tongue and swallowed with a frown. A tremor passed through her body, making her own curves ripple and shudder. Then, just like that, it was over. “Okay,” she said, placing the vial carefully on a cabinet. “Here we go…” 

“H-how exactly does this work?” said Ruby, as Yang approached her. “What exactly are you doing to–” Yang stuck her head in her cleave. “–dooooooo?!” As Ruby screamed in shock, her sister slipped inside her, sucked up and out of her clothes like a clump of dough out of a bowl, leaving them to fall to the floor in a pile. Weiss and Blake stared in shock. 

For several seconds, Yang’s legs continued to kick, as if she were a swimmer trapped in the middle of a dive. Then, with a schlup, they simply slipped into Ruby’s boobs and vanished. They rippled a little, like disturbed water, and with a tremendous boing–

She squealed as her boobs exploded, filling her corset and then some. All of a sudden, it felt painfully tight, so tight she actually found it hard to breathe. Heart pounding, she struggled to loosen it. Her boobs spilled over its rim like bread over the edges of a baking pan. 

As Ruby regained her breath, Weiss and Blake started at her in shock. “Y-Yang?” said the latter. “Is she still…?” 

Ruby’s boobs bounced, quite noticeably. It took all Ruby’s self-control to keep herself from moaning. 

Blake snapped her book shut with a thwap. “I’ve changed my mind,” she said, snatching up the Dust vial. “I’ll help you too.” And before anyone could say anything, she’d sprinkled a few little motes onto her tongue and swallowed. Her entire body seemed to ripple and shimmer. 

Placing the vial back on the cabinet, she made her way over to Ruby, sizing her up as she approached, and finally stepped around her. 

“Wh-what are you doing?” Ruby asked, as Blake crouched behind her. 

“You don’t want to be top-heavy, do you?” asked the Faunus. And just like that, she pulled down Ruby’s panties and stuck her head into her ass. Schlup! 

Ruby screamed, gritting her teeth and spasming in ecstasy, as her buttocks slurped Blake up out of her clothes and inside them, swallowing her in instants. As Blake’s feet disappeared into her ass, it exploded with a boing, reaching the hem of Ruby’s dress and straining to escape it. Ruby squealed in surprise. She’d never be able to get her panties back up again. 

Struggling to regain her breath, Ruby turned slowly to face Weiss. 

“Wh-what?” said the Schnee heiress. “What? Why are you looking at me like that? You think you’re going to pressure me into sticking myself in you too?” 

Ruby was barely even looking at her. Breathing hard, she slammed her legs tight and released an airy breath. “It feels so good…” she said, hand creeping to her groin. 

Weiss turned a deep shade of red. “On second thought, I can always wear my costume next year.” Snatching up the Dust vial, she downed every last speck, tossed the empty glass aside and threw herself straight at Ruby’s dripping pussy. 

Schlup! 

This time, as Weiss slipped wiggling into the oozing canal of her sex, Ruby dropped to her knees and threw back her head and screamed in wild ecstasy. 

Several minutes had passed by the time she recovered the strength to clamber back to her feet and stumble into the bathroom. Studying herself in the mirror, she shivered in appreciation. Weiss had plumped her pussy into a pair of fat kissers, thickening her thighs as well for good measure. Now her costume fit her snugly. 

She just had to find someone capable of filling her.