A Bet on Who Develops Them Better
"Ooooh♡♡♡"
The moment I yanked the thick string of anal beads free in one pull, they slid out smooth and easy, popping free one after another with wet little sounds. Mom and Dohee, who still could barely take anything larger than the small beads, stared at Seohee's stretched-open hole with naked envy, already getting worked up.
Seohee was twitching facedown, half-fainted from the aftershocks.
"I'm going to train you both until you're like this, so look forward to it."
"Yeees♡♡ Please develop Mommy's asshole however you want, Master—use it as much as you like♡♡"
"M-me too♡ I'll stretch my asshole wide, so fuck it with your cock, Oppa♡♡"
Showing them Seohee's fully trained hole had clearly lit a fire under them. Mom's eyes sparkled as she begged to be developed right away, while Dohee looked like a switch had flipped—she was already swaying her hips like a bitch in heat.
"Come on~ Please turn Mommy's big, filthy asshole into another pussy♡"
"Please use Dohee's asshole like a pussy too♡♡"
They bumped their asses together, both of them desperate for the training. Mom's massive rear and Dohee's firm, athletic cheeks clapped against each other, flesh rippling in waves that only made the invitation more shameless.
"First things first—we need to get you both to the point where something like this slips right in."
Squelch. Squelch. Squelch.
"Ooh♡♡ Nngh♡ Mommy's asshole feels so weird♡♡"
"Ooooh♡♡ I—I'm already cumming from my asshole♡♡"
They were still only at the start of their training. Mom couldn't quite make sense of the strange sensation yet, but Dohee was already taking to it like a natural-born anal slut, feeling every bit of it properly.
Fsssshhh♡♡
"I came from my asshole♡♡ Haaah♡♡"
Since Dohee had gotten there first, I pulled out a thicker set of anal beads than the ones she'd used before and pushed them into her hole.
"Ooh♡ Something even bigger just went in♡♡"
"Dohee got them first… Your son’s mommy can take it too, so put the bigger ones in me♡♡"
The thicker beads alone were enough to send Dohee over the edge; her body went limp and she collapsed.
Watching her, Mom seemed to catch a competitive spark. She still wasn't feeling it properly herself, yet she was already begging to be stretched the same way Dohee had been.
"It'll still be hard for you, you know."
"I can do it♡ Mommy's a masochist pig who can feel it from her asshole too♡♡"
With her pleading like that, I pushed in beads the same thickness as the ones I'd given Dohee.
"Ooh♡♡ Th-this is thick♡♡"
"Want me to pull them out?"
"No, it's fine♡ The little bit of pain actually feels even better… nnngh♡♡"
Mom was still struggling to take them, but the pain only seemed to push her further—her pussy was already drooling steadily down her thighs.
"Both of you… so fast…♡"
Seohee had come back to her senses. She looked at the beads stuffed into Mom and Dohee and gave a small, satisfied nod.
"Unnie…… I'll train her…♡"
"All right. Then I'll train Mom. Want to bet on who develops them faster?"
"Fine…… If I win……"
Seohee leaned in and whispered her prize into my ear. I told her I understood, and the two of us started our separate training sessions. The deadline was the end of the day—whoever got their girl feeling more from her asshole and taking something bigger would win.
"Well then, since we've got a bet going, let's get started properly, Mom."
"Mm♡ Hurry up and train Mommy as much as you want, son♡♡"
And that was how we somehow ended up with a wager. Losing wouldn't cost me anything, but as their Master, my pride wouldn't allow a defeat—so I fully intended to train Mom properly.
I wasn't aiming to make either of them into Seohee in a single day, but I was going to get a lot further than anyone might expect.
"How's this feel?"
Squelch. Squelch. Squelch. Squelch.
"Ooh♡♡ Nngh♡ I'm feeling it♡♡ I can feel it in my asshole♡"
Just being trained was already a massive turn-on for Mom. And when I forced the pace a little harder, trying to rush her development, that masochist streak of hers only made her melt harder under me.
I hammered the beads she'd been struggling with only moments before, and Mom came lightly with a full-body shudder, pussy juice running down her legs as her hips jerked.
"That's my mom for you. You've barely started training and you're already clamping down on the beads like a filthy slut."
"Heeeh♡ Mommy's a masochist pig♡ More… develop me more so I can serve your cock with my asshole♡"
Bet or no bet, Mom just wanted to start servicing me with her hole as soon as possible—she was desperate to be trained until she was ready to use.
"Good. Then we should do something more effective than this."
"Nnngh♡♡"
I looked down at her with a wicked smile. Anticipating whatever nasty thing was coming next, Mom ran her tongue over her lips.
"Unnie…… Unnie……"
"Heeh♡ Heeeeh♡♡"
While Oppa trained Mom, Seohee had to develop her older sister Dohee. Looking at the situation, Dohee had seemed the easier one to train, which was why she'd chosen her—so she needed to get results fast.
If I win……♡
Just thinking about the prize she'd get from Oppa if she won made her pussy soak through at once, slick running down her thighs.
But Unnie, still wrecked from her anal orgasm, wasn't responding at all—just twitching with that stupid little smile, completely out of it.
She pressed down hard.
"Nngh?!♡ S-Seohee?!"
Stepping on Dohee's face and pinning it finally snapped her back to awareness, though she still didn't seem to understand what was happening.
With Dohee, once she went fully into heat she became almost impossible to train properly—so Seohee deliberately brought her back to her senses, intending to keep her as clear-headed as possible while she worked.
"If you pass out…… that's a punishment."
"What do you me—ooooh!!♡♡"
Seohee didn't bother answering Dohee's confusion. She simply grabbed a small dildo and drove it straight into Dohee's pussy. She was already so soaked that the little toy sank deep without the slightest resistance.
Squish!! Squish!! Squish!! Squish!!
Squelch!! Squelch!! Squelch!! Squelch!!
"Ooooh?!?!♡ Wait, this is—oh goood!!♡♡"
Seohee seized both the dildo and the anal beads and started thrusting them in alternating rhythm, mercilessly. Even through her shock, Dohee couldn't keep her mind straight under the sensations flooding her pussy and asshole at once.
Being put through something this humiliating by her little sister didn't spark any real resistance—only more heat.
"Oh goood?!?!♡♡♡"
Pleasure-weak as she was, Dohee came almost at once, disgracefully soaking her sister's hand. Even mid-climax she clenched tight around everything inside her, as if refusing to let any of it slip free.
"Five more times…… from now."
"I-I'm gonna die♡♡"
Seohee's method was the same one she'd used on herself—pounding the pussy at the same time as the asshole so the sensations in the rear hole got wired straight into pure pleasure.
Dohee was already sensitive enough, and she was already feeling plenty from her asshole, so what she was getting wasn't pleasure mixed with pain—it was double the pleasure. When Seohee started thrusting again without giving her a break, Dohee came and came, completely unable to hold herself together.
"Heeeh♡ Hrngh♡ Nngh♡"
Seohee kept working both holes until Dohee had gone over more than five times. Dohee twitched on the floor like a fish hauled up on land, mind blank. Even then Seohee decided it wasn't enough and started again—until Dohee's eyes rolled back and she finally fainted under her little sister's hands.
"Haa…… Now…… it really starts♡"
Looking down at the sister she'd just knocked out, Seohee allowed herself a faint smile and reached for the next toy.
"Oooh~ Seohee's really going at it. As her mother, I can't lose to my own daughter, can I?"
"B-but I can't—hrngh♡"
Mom was on all fours, cold sweat running down her skin, her whole body trembling. In my hand was a large syringe—no needle—currently pumping white liquid into her ass. One liter at a time. Five liters were already inside her.
Her belly hadn't ballooned out like something from a comic, but her lower stomach had rounded slightly and gone firm.
"I'll stop at this for now. Can you hold it?"
"If I relax even a little—nngh♡—it's all going to come pouring out right now…"
For all her distress, Mom's face still wore a filthy smile—the situation itself had her completely turned on. Even knowing that the slightest loss of control would send the white liquid flooding out of her, her pussy kept dripping steadily.
"Then I'll plug it with this."
"Nnnngh!!!♡♡♡ T-too biiig♡♡♡♡♡"
What I pushed into Mom's asshole was an anal plug—thick enough that it looked like a real struggle for someone only just starting to get developed.
"Want me to leave it unplugged, then? Going to cum it all out right here?"
"Haa♡ Haa♡ I'm sorry♡♡ Please put it in♡ Plug Mommy's asshole with the anal plug♡"
Even for her, the thought of emptying an enema in front of me and her daughters was too humiliating. Mom chose the plug instead.
With this, I've got the win locked down~
I'd picked something with serious girth—as thick as I figured we could reasonably get to today. Even Dohee wouldn't be easy to train up to taking something this size.
Squelch!!
"Ooooh♡♡ It went in♡♡ The whole thing went iiiin♡♡"
It wasn't especially long, but the thickness was enough that it should have brought real pain—yet the overwhelming need to empty herself drowned most of that out. She barely felt the stretch in her hole at all.