Rachel sat through dinner, feeling very anxious about the little vibrating egg stuffed in her twat, sure that their mother was going to hear the little thing humming away inside of her. Mother did not notice, though. As usual, their mother picked silently at the food Lucy had prepared, and then excused herself to swallow sleeping pills, before drinking herself into a depressed stupor in her bedroom. Rachel, her pussy very happy at being kept wet, could not wait to see what Lucy would teach her next.
Curious about the new toys they'd obtained from the dirty sex shop, Rachel eagerly followed Lucy into her bedroom, where her sister snuggled close to her, nude, on the bed and began to kiss her. Lucy's hands caressed her skin, cupping Rachel's bottom, toying with her tiny asshole, something that made Rachel squeak into her mouth. When Lucy parted her legs and rubbed at her cunt, Rachel responded with a delirious little moan that made Lucy's own pussy throb needily.
Lucy had never before fucked for an audience, even an audience of one. Letting Luke use her in front of her little sister had switched up Lucy's perversity another notch, and she kept replaying the scene in her head. It had been so filthy, laying on her back, letting the man spread her legs, and then whoring herself out for his pleasure, while Rachel toyed with her cunt and watched. She regretted not recording it with the webcam, but there would be other opportunities. Now, she had other fun things that she wanted to introduce Rachel to.
In watching the various porno videos, Lucy had come to the conclusion that Rachel most enjoyed the degrading, mean girl porn. For whatever reason, Rachel pictured herself as one of the girls being abused by the mean girls. Each time one of these videos played, her sister's inexperience little pussy would start working itself into a frenzy. Lucy, for her part, also enjoyed watching the little sluts in the videos get used like sex dolls, but in her own imagination she was the mean girl, controlling the submissive slut. Having her own slut, Rachel, was perfect! If Rachel wanted to get off to mean girl porn, Lucy was going to make it happen for her. It just had to be done in steps.
"You've been keeping your pussy wet and happy," Lucy said, breathily, breaking the kiss.
"Uh huh," Rachel replied, looking at her sister with wide eyes as Lucy coated her fingers in the sticky secretions from Rachel's cunt.
Lucy brought her fingers to Rachel's mouth and pushed them inside, smiling as her sister licked the taste of her own pussy from them. She followed this by pushing her tongue back into Rachel's mouth and pulling on her nipple roughly, making Rachel squeal. She was delighted as Rachel shook with pleasure at the pain in her tit. Rachel dipped her hand between her legs and rubbed at her cunt, ensurung it stayed happy, just as Lucy had taught her.
Lucy broke away and located the white vibrator, flicked it on, and passed it to Rachel.
"Play with your cunt while I get some things ready, alright?"
Rachel nodded, accepting the vibrator, settling back against the pillows, and pushing the toy against her fuckhole as Lucy worked at the laptop. Having only had her one, ruined orgasm earlier in the day, Rachel found it very hard not to make herself cum, but she was determined to do it right. If she was good, if she didn't cum, then maybe Lucy would put her tongue into her cunt again. That had been better than any of the toys, even though Rachel felt that it probably wasn't something that they should be doing. Being naked with her sister, letting Lucy touch her and kiss her, had been naughty, but allowing Lucy to put her tongue between her legs and lick her had felt doubly so. It crossed the line into real incest, she knew, but it had really made her pussy wet and happy, which she knew was the most important thing. That's what Lucy had taught her. Not to disobey her cunt. It should always be happy, excited, and getting what it needed.
Lucy finished what she was doing on the laptop and moved back, picking up one of the new toys from her nightstand. This one was the little strap with the red ball. It was a gag ball, like the one she'd seen some of the girls wearing in the videos. Rachel's eyes shifted from the ball, to Lucy, then to the screen, where she saw another girl with two toys, playing with her cunt. One of the toys was clipped to the girl's finger, and she was vibrating it against her clit, while she pushed the other inside of her cunt. The girl shook and moaned, as she stared into the camera.
This was different though. The girl in the video was looking at her, looking at Rachel. It wasn't a video. It was another girl, and she was playing with her pussy as she watched Rachel play with her own pussy.
"Lucy it's -" Rachel began to say, but Lucy put the gag ball into her mouth and snapped the strap behind her head, muffling whatever Rachel had been about to say.
Lucy picked up another toy, this one the collection of nylon straps with the fake penis attached to them. She put the straps around herself, and cinched them into place. Rachel pulled the toy away from her cunt before she could cum, shaking, watching the fake penis bobbing up and down. Lucy got behind her, in the familiar position that Rachel had become used to, in which Rachel rested against her sister's bare breasts. The girl moaned loudly as she watched Lucy position the fake penis between Rachel's spread legs, where it settled between her wet labia, stretching them to either side of the rubber shaft.
Lucy gripped one of Rachel's tits in her hand, then took the white vibrator away. She set it aside, then spread Rachel's pussy and took hold of the little lead on the egg in her cunt, pulled it free with a wet smack, and then Rachel felt very empty. The egg had been in her cunt nearly the whole day, and it had begun to feel very normal having the vibrations constantly teasing her twat. Without it, she felt strange. To compensate for the sudden void, Rachel found herself sliding her cunt along the length of the rubber shaft as she watched the girl on the screen shove the toy inside her cunt.
"Good girl," Lucy whispered in her ear as she squeezed her breast, "Watch your friend. Look at how much fun she's having with her cunt, just like you."
Rachel did watch, reflexively rubbing her pussy along the fake penis, the little ridges stimulating her clit as the girl on the screen moaned.
"Did you like watching Luke fuck me?" Lucy asked.
Rachel groaned, remembering the sight of her sister's legs pushed back as the man roughly shoved his cock into her, slapped her face and called her names.
"I was such good girl for him, wasn't I?"
"Uh huh," Rachel mumbled through the gag.
Seeing it happen, right in front of her, had gotten Rachel so excited. It was better than the videos, because it had been real, scary, but so oddly exciting. Lucy had been good for him, allowing Luke to use her helpful pussy to take care of his cock. Rachel felt so glad that Lucy had shown her how to be good, and even though it was frightening, she wanted to try it for herself someday.
Rachel's pussy slid along the length of the penis, but when she moved too far along it, the head of the toy slipped into the entrance to her wet pussy