Kim shrinks Becky down, too

By: Cheese111

Becky is first to return, kneeling down in front of the doll house and looking in through the opened wall. You give her an awkward wave, making her giggle.

"Teehee, you're so adorable. C'mon, come get some sugar." She pursed her lips, waiting for you. Though you were certain she wouldn't like the taste, you were not one to disappoint your girlfriend. With a short run up you threw yourself at her, the big lips catching you and feeling comfortably soft. Becky sneaks in a finger behind you to keep you in place as she plants an enormous kiss across your chest. She adjusts herself up to put one on your face too, but the suction of her smooch is enough to pull your head in between the thick lips. She simply presses them together, engulfing your head in a strange sort of kiss. It felt nice enough and with her finger behind you there wasn't much you could do to stop it anyway.

"Mmm, I can't wait to have a sleepover here. I wonder if your sister will let me sleep with you." She said seductively. Normally you'd be over the moon at hearing this suggestion. But after today's events you weren't so sure. It sounded like she wanted you smothered in her tits or worse, stuffed in her pussy all night. You love Becky very much, but that was definitely over the top.

Kim returns soon after, holding two glasses of fruit juice. She sets them down on her desk before opening a drawer and taking an old plastic bottlecap from it. She blows the dust away and gives it a quick spit-shine before scooping a small amount of juice from her glass and setting it down on the living room table. For all her disgusting perversions, she did seem to care about you in her own strange way. You weren't so enthused by the offering.

"What's wrong, little Willy? Don't you want a drink?" She cooed.

"I'm still stuffed with Becky's offering." You reply, patting your belly. She nods in understanding and sits back on her bed. For some reason she appears fixated on Becky, watching your girlfriend drink up. Apparently Becky was thirsty, as she downed the whole glass.

"So Kim, you gotta tell me. How did he end up this size?"

"Heh, funny story that. I learned that apparently futa cum has some extra properties. Don't worry, they don't normally affect anyone. But if you distill it you can concentrate the effects. As a prank I wanted to see what would happen if I slipped some in Will's drink last night. Then today I find him stuck to my balls, trying to get my attention." A sudden shiver of concern ran down your spine. Not so much about the casual nature of her story, but about the events of the last few minutes. Kim only went to get a drink after Becky made that comment about her dick. She wouldn't have...

"So does it work fast?" Becky asked, enthused by Kim's story. Your sister fidgeted nervously before giving a most ominous reply. "We'll find out soon enough."

"What do you mean? Wait... Did you?" Becky went pale as she realized that her drink tasted a little odd for fruit juice. She'd chalked it up to it being some exotic blend she'd not had before. Kim smiled broadly and sat back, eager to observe the shrinking in action. There were still some possible variables. Given the amount of time between her giving her little brother his drink and him shrinking it could take hours before something happened. Also she had no idea if this trick would even work on women. She was surprised to see Becky afraid though.

"What's wrong? Don't you want to be tiny like your boyfriend? Since he's apparently better sized for you I figured you'd be happy. And you won't have to worry about me having to hold back either." She cooed with false enthusiasm.

"Are you crazy? Why didn't you ask me if I wanted to be shrunk?!" Becky stammered. Her irritation got a side of fear attached as she saw her perspective drop slightly. Was she just imagining it or did the drink already take effect? "Reverse it, right now!" She commanded.

Kim nervously scratched the back of her head. "Well, uhm... I don't know how."

Becky's shocked "What?!" was met with your own tiny cry of exasperation. Of course she'd not bothered to study it proper. For all her studious and careful pretenses Kim was still reckless as ever when she got excited about something. And judging by her steadily growing erection, she was very excited to see Becky shrink. Your girlfriend stormed across the room, leaping at Kim, but your sister was now twice as tall as her. It was about as hard as keeping an ornery toddler at bay and only minutes later even that wasn't accurate anymore.

"You can't do this." Your girlfriend cried out as Kim's fingers wrapped around her. She was no larger than a doll at this stage. She pounded on Kim's hand to no avail as it carried her over to the doll house. Kim held on to her for a few seconds longer before setting her down. You opened the front door to find your girlfriend now down to your size. It made you wonder how you didn't notice this happening last night, but before Becky and you could reunite Kim made it clear she had plans for the two of you.

"Aw, you're so cute together. This is gonna be the best sleepover ever." She announced proudly.