"There you are! How dare you ignore me like that!" Noire exclaimed as Uni and Nepgear flew in. "What makes you think it's a good idea to leave the Basilicom looking like…like…THAT?! And Nepgear, too? I know it's not really my place since I'm not your sister, but I can't believe she would also let you leave like that, unless you did the same to her!" Noire sighed. "You and I need to have a talk, Uni."
"Yes, we do." Uni agreed. "You've been very stressed out lately."
"Yes, and you certainly aren't helping. So, Nepgear, can you please leave? Uni and I need to-" Noire was suddenly interrupted by both Uni and Nepgear grabbing her and pulling her towards Noire's bedroom. "H-hey, what are you two doing?! Let go of me!" Noire tried to break free of their grasps, but they were able to hold on surprisingly well, and before she knew it, Noire was thrown onto her own bed. "Uni, what's going on here?!"
"We're gonna help you let off some steam." Uni said, and grabbed Noire's skirt, yanking it down and exposing black panties underneath. Noire screeched.
"H-HEY! WHAT ARE YOU-?!" Noire said, but Nepgear jumped onto the bed and covered her mouth with one hand.
"Shhhhh…just let us take care of everything~" Nepgear said as Uni grabbed Noire's panties. Noire tried to thrash around, but Nepgear climbed on top of her and sat down on her stomach, facing her as Uni pulled her panties off, revealing her bare pussy, shaven just like her sister. Noire tried to keep her legs closed, but a long tail attached to Uni's backside managed to wrap around both her legs and pulled them apart, exposing everything.
"Mmmmmffff?!" Noire yelled, and tried to push Nepgear off of her, but Nepgear grabbed her top and yanked it down, allowing her breasts to come free of their confines, bouncing around from the movement. Noire's face was a bright red, and she only blushed deeper as Nepgear grabbed her breast and started to squeeze it, the soft flesh giving way to her tender fingers.
Meanwhile, Uni removed the small piece of clothing covering her groin, and her new dick sprang free. Unfortunately, much like her chest, it was smaller than Nepgear, but it would be enough to get the job done. With the tail still attached to her, holding her legs open, Uni approached her and grabbed onto her waist. Uni's touch made Noire jump, and she moaned into Nepgear's hand as Nepgear rubbed her nipple with her thumb. Uni watched as Noire started to become wet from the stimulation of her chest, which only worsened when Nepgear pinched Noire's nipple and twisted it, making the girl's entire body shudder, and even more so as Nepgear pulled at the nipple, before letting go, watching as the breast bounced back into place.
When Noire seemed sufficiently wet, Uni pushed her dick up against Noire's wet lips. Noire made a noise of confusion as she felt the strange object against her, and that confusion turned to pain as Uni pushed her head inside. She screamed into Nepgear's hand, still firmly over Noire's mouth even as she played with her breast. Uni groaned as she felt Noire's tightness around her dick, but continued on, pushing in deeper, feeling Noire's body resist her as it shook. Noire thrashed around violently as the pain increased, but even so, there was something else as well, a strange feeling of pleasure that, even through the pain, felt amazing. And as Uni pushed herself deeper and deeper, the pain slowly turned into pleasure, and Noire felt herself beginning to enjoy it. Then, Uni was fully inside. Noire had sweat dripping down her face as Uni sat inside her for a while.
Eventually, Uni pulled out and slammed her body back inside, her balls slapping against Noire's thighs as she went in. Noire's body lurched, her breasts jiggling as she shook, a muffled moan escaping her lips. Nepgear continued to twist and pull at her nipple, watching as her chest moved up and down with her rapid breathing. Uni pulled out again before she went back in, gently pushing against her, but quickly gaining speed and force as she did it again and again. Noire's eyes began to roll up in the back of her head and she kept moaning.
"Uni, I have an idea." Nepgear said. She finally got off of Noire, letting go of her mouth, but didn't say anything as Nepgear leaned over and whispered in Uni's ear. Uni smiled and nodded. She let go of Noire's legs, but the tail wrapped around Noire and lifted her up, flipping her over and setting her back down on the bed. Noire was still recovering from the penetration, so she was a bit cloudy in the head, and wasn't able to react as Uni grabbed onto her ass, her hands sinking into the flesh as Nepgear moved to her front and grabbed her northern cheeks.
"Wh-what…?" She asked, before she felt something get shoved inside her mouth so hard that she gagged. Her eyes went wide and she found herself staring at Nepgear's belly. She realized what was going on, and was about to try to speak when she felt Uni penetrate her pussy from behind, making her moan again, causing Nepgear's dick to vibrate inside her mouth, making Nepgear moan. Nepgear grabbed her by the hair and started to thrust in and out of her mouth, bumping against the back of Noire's throat every time and causing Noire to gag at first. Meanwhile Uni held her ass cheeks tightly as she slid in and out of her dripping wet pussy, moaning as well as she thrusted. Noire was trapped between the two dicks and was unable to do anything about it, getting overwhelmed by the pure pleasure she felt. She'd stopped gagging from Nepgear's dick, and actually sort of enjoyed how it felt for the dick to come in and out of both her ends. She even helped out by flicking her tongue against the shaft, feeling it throb in response. All three were now left moaning from the experience.
Noire could feel something else coursing through her, not just the pleasure. Something…that felt wrong, but oh so good. It felt like a craving. She wanted more. She wanted them to go harder, faster, she wanted them…to cum.
As if reading her thoughts, they did speed up, Nepgear bending forward as her hips moved back and forth, feeling the pressure building, her dick throbbing painfully as Noire's tongue wrapped around her shaft. For Uni, she felt that same pressure, similar to when she needed to masturbate normally, but just a little different. Some part of her, whatever rational part of her remained, knew she shouldn't cum inside of Noire, but she wanted to, and that part of her brain easily overwhelmed her. So, with a moan, she shoved herself all the way inside as she came. She felt her semen explode out of her dick and into her sister. She felt it fill every possible crevice, every hole.
At the same time, Nepgear also came, her cum shooting down Noire's throat, the warm sticky fluid making her gag for a bit before she happily swallowed every last drop. Once both had emptied themselves, they pulled out and Noire collapsed onto the bed, breathing heavily. As Nepgear and Uni looked down at her, her body seemed to…flicker a few times. She flipped onto her back, semen leaking from her pussy. She flickered again, and Uni and Nepgear smiled as they saw the same marking they had appear on her thigh. She looked up at them with a smile.
"C-can we go again?"