Kitty knew instinctively that changes would be coming in the third week. Things seemed to be constantly escalating between her and her new doms, so it only made sense that their third and final week would hold new humiliations.
She wasn't disappointed.
When Kitty exited her room on Sunday morning, she found that Becca and Laura were already awake, changed into their dominatrix outfits once again, and impatiently waited for her in the living room.
"Good morning, darling," said Laura with a welcoming smile. "As you can see, I've called another family meeting. Why don't you take your clothes off? I think it will get you in the right frame of mind to hear our news."
By this point, Kitty had learned not to hesitate when her mommy gave her commands. Although she still felt the sting of humiliation as she stripped naked in front of her gorgeous, dominant mother and sister, the shame only added to her pleasure now.
She stripped her pajamas and panties away fully and stood naked and shivering before her Mommy and Mistress, nipples hard points of desire, her pussy already moistening in anticipation of her Mother's new commands.
Laura's eyes were filled with pride as Kitty sank to her knees without being told, taking an inferior position to her betters by force of habit alone. "I think it's fair to say that our little family experiment has been a complete success," said Laura fondly, cupping her naked daughter's cheek in a loving hand while looming above her in her obscene dominatrix outfit. "But we have so much more to explore. Our outing last night opened my eyes."
"Good news first," said Laura briskly, gesturing to Becca, who retrieved the tiny key from between her breasts with a huffy little sigh and handed it over to her mom. "We are dispensing with your chastity starting today. You proved your complete obedience beyond a shadow of a doubt last night. It's no longer necessary," said Laura, dangling the key in front of her wide-eyed eldest daughter and allowing her to take it in shaking hands.
"Now for the... more challenging news," said Laura, her eyes glittering with cruel amusement, "Your sister and I have decided that we cannot truly help you until we all understand the full depths of your submissive tendencies."
Laura's deep blue eyes flicked over to share a silent, meaningful glance with Becca, who winked back.
"To that end," said Laura, turning her heated gaze back to the obedient sub at her feet, "We think that in our last week together, it makes sense to try out some... new roles. To see if further submission will finally satisfy your dark desires, darling."
Something about how her mother had said it sent a thrill of arousal and anxiety through Kitty's fluttering heart. "New roles?" she asked meekly, her soft eyes upturned to her dom with eager submission. "I... I'll do anything for you, Mommy," she added with a hopeful smile, silently begging her mother to be merciful.
"Good girl," murmured Laura, her finger tracing down to touch the "Mommy's Girl" choker that her daughter still wore. "I need to get some work done at home this Friday. You will become my secretary."
Kitty couldn't help but tilt her head in confusion. Working answering her mother's calls and helping her with paperwork didn't sound particularly sexy, but the look in Laura's eyes promised that it would be an erotically humiliating experience, so Kitty simply meekly nodded and said, "Yes, Mommy."
Then Becca stepped forward, fierce and dripping with sexual menace in her skin-tight catsuit. "Until then..." she said, her eyes lingering on Kitty's naked body, "I have another new role for my beloved older sister."
Becca stalked forward and placed a possessive hand on Kitty's head, stroking her hair. "You know how I always wanted a dog? Do you remember why Mom would never let me get one?"
"She s-said that she wasn't sure you were responsible enough," said Kitty, her voice trembling and her face growing pale as her eyes nervously darted back and forth between her Mistress and her Mommy.
"Welllll, Mom saw how incredibly responsible I've been this past week managing your orgasms, and decided that I can finally get a cute little puppy all my own!" said Becca with an evil giggle. Her constant stroking of Kitty's hair suddenly took on a sinister implication.
"M-mistress, I..." whimpered Kitty, looking away and feeling waves of shame and arousal crash over her at the degradation of being forced to become her little sister's loyal pet. The last shreds of her pride ached and tore at her heart as she surrendered to the feeling, nuzzling up against her mistress's loving hand.
"That settles it," said Laura crisply. "Later this week you will serve as my secretary. Until then, do your best to act as your sister's puppy."
Kitty looked up at her mother and sister where they stood, perfect and untouchable above her.
There was just one week left until she would leave them behind and start a new life.
Did that fact excite her, or disappoint her? She was no longer sure.
...
Monday through Wednesday, Kitty was her sister's dog.
When she came down the stairs Monday morning, Kitty wasn't quite sure what to expect. What did it mean to be Becca's puppy? Was she supposed to act super enthusiastic and loving toward her Mistress? She didn't think that Becca meant anything more literally than that. But she was in for a rude awakening. When Kitty entered the dining room, Becca paused mid chew in a mouthful of cereal, her eyebrows scrunching together as she laid eyes on her puppy for the week.
She stood, looming above the suddenly bashful Kitty, making her feel the height difference as her eyes ran coldly over her older sister's body. With an arched eyebrow and a grimace, she turned to Laura, who was sitting at the table with a look of faint amusement on her perfect face.