A Precarious Line
A Precarious Line
"Aria, no matter what, outside..."
"Hehe, then shall we save this as a treat for when we get home?"
Aria put the collar, the hairband, and the maid-style bikini into the shopping bag just like that.
While Aria went to pay, I took a quick look around at the other products on display in the shop.
It was the kind of merchandise that made me naturally understand why this store was tucked away in a corner even more remote than the subculture section, hard to find, and covered with blinds so no one could see inside from outside.
To put it bluntly, there were quite a lot of very risqué clothes and accessories.
It hit me all over again that I'd actually brought my little sister to a place like this.
No, thinking about it the other way, maybe it was precisely because Aria loved me that much that I'd found the courage to bring her somewhere like this.
I'd gotten a lot closer with Seo-yeon lately too, but even Seo-yeon would probably be inwardly horrified if I brought her here.
"Is this one at least a bit better?"
I picked up a hairband with cute cat ears, different from the maid-style hairband we'd bought earlier.
It seemed to be part of a set, because two other products came attached to it.
"..."
One of them was fine. It was just an ordinary pair of gloves shaped like cat paws, with cute toe beans.
The problem was the other one: a cat tail.
Because the design made it blatantly obvious where you were supposed to insert and secure it.
I quietly put it back on the display shelf.
This was way too obviously a sex toy.
Of course, knowing Aria, she'd probably be happy even if I suggested buying something like this, but for now I didn't want to be the one to bring it up.
I was aware that my views on romance were old-fashioned. But even taking that into account, a man and woman who weren't even officially dating or married yet using something like this was going too far.
"Brother, I've finished paying."
"Shall we head home then?"
"Yes!"
My load was already too heavy to enjoy any more time here.
Most of the items in the shopping bags were swimsuits, so they weren't heavy, but they took up a lot of space.
"By the way, Brother, what were you looking at?"
"Just this and that. There were a lot of interesting products."
I deflected it casually.
There was no way I could answer that I'd been looking at sex toys.
Aria's curiosity seemed to grow at my reaction, and she started looking around the shelf I'd been examining.
Then, she reached out toward one product.
"Oh, this is cute!"
What Aria picked up was the exact set I'd been looking at just moments before.
Aria put the cat-ear hairband on her head, slipped the glove onto just one hand, and whispered while waving the gloved hand like a cat batting its paw.
"How is it? I'm a baby kitten who loves you very much, Brother."
"It is cute, but..."
The end of my sentence trailed off without thinking.
Having already seen the tail in her ungloved hand, I couldn't bring myself to call it purely cute.
Aria must have noticed my gaze flicking that way, because she examined the tail from different angles and asked me.
"By the way, how do you wear this tail? This part seems like it would get in the way if you attached it to clothes..."
Aria pointed at the blunt tip made of stainless steel.
Should I tell her or not?
From her puzzled expression, she clearly had no idea, but if I explained it I'd be embarrassed, and if I didn't, I was afraid she might actually buy it.
It lasted only an instant, but I must have gone back and forth dozens of times before steeling myself by telling myself this was sex education for my little sister.
"That's..."
Since it wasn't a topic to discuss out loud, I leaned in close to Aria and whispered in her ear how the tail was worn.
When the whisper ended, Aria's face flushed bright red and she even stammered.
"I-in, in your bottom...?! Th-that's unsanitary!"
"I only heard about it secondhand too, but that's what they say."
Aria was an adult, so she seemed to have basic sexual knowledge, but apparently she didn't know much about this kind of thing.
Actually, not knowing was normal.
Guys might know about this stuff because it shows up often enough in adult videos, but there was no way Aria went around watching things like that.
Aria avoided my gaze and asked cautiously.
"So, Brother, is this kind of thing your taste? Like, you'd want to put something like that on me..."
"Do I look like someone who'd be into that?"
"Well, no, but still, there's always a one-in-a-million chance. If you're interested in this kind of thing too, Brother, then I'd have to study hard..."
It was a commendable sentiment, but the topic of conversation was not commendable at all.
What would she even use that kind of studying for?
"Don't worry. I'm not interested. So put that down and let's head back soon."
Honestly, if we're just talking about interest, it wasn't like I had absolutely none, but at least my thoughts hadn't changed from before.
Maybe after Aria and I had a deeper relationship someday, but what would I even do with something like this if I bought it now?
However, Aria seemed to make up her mind about something at my words, and walked over to the register and held out the product.
"I'd like to pay for this too, please."
"Wait, Aria. Why that?"
It wasn't even a swimsuit, and I'd just said I wasn't interested.
I couldn't understand why Aria was buying it.
"The ears and gloves are cute. And, well, the tail might come in handy someday..."
Honestly, I wondered if a day to use this would ever come.
Still, it was her own money, so I didn't stop her from buying it.
When we stepped out of the shopping mall, the sun was slowly disappearing beyond the concrete forest.
We took a taxi home.
It was close enough that we could've taken the bus, but I wanted to avoid even the slightest chance of running into someone we knew on the way back with purchases like these.
"We're home~"
Aria's voice echoed through the empty house.
Instead of answering, I held out the shopping bags to Aria.
Aria took the pile of shopping bags and said.
"You worked hard, Brother."
"Worked hard, nothing. I offered to carry them. They were light anyway, so it wasn't hard at all."
"Still, I was able to shop comfortably thanks to you. Thank you, Brother."
We naturally headed to our respective rooms.
Aria would need to organize her things first, and I needed to change clothes and start preparing dinner right away.
I changed into comfortable clothes and stood in the kitchen.
I opened the fridge to check what was inside.
"Let's keep it simple today."
I trimmed the chicken thighs into bite-sized pieces, placed them skin-side down, and grilled them until golden brown.
In the middle of that, I added onions and grilled them together, mixed tsuyu and water in the right proportions, tasted it, then added chicken stock for extra seasoning and a bit of cheongyang chili pepper to cut the sweetness with some heat.
Finally, I poured in beaten eggs and cooked them just until barely set, then placed it all over rice and topped it with crushed seaweed flakes and thinly sliced green onion.
After finishing the oyakodon, I went to Aria's room and knocked.
"Let's eat, Aria."
"Just a moment! I'll be right there!"
From inside the room came the sound of hurried footsteps along with Aria's flustered voice.
I went back to the living room and waited, hoping it wouldn't get cold, and fortunately Aria came out quickly.
"Sorry. Was I late?"
"No need to apologize. Let's eat before it gets cold."
Aria took a bite of the oyakodon and said, as if surprised.
"Japanese food today?"
"Yeah. I was thinking about how to use up the frozen chicken thighs, and this seemed like the simplest and tastiest option."
When I'd opened the fridge, I'd spotted frozen chicken thighs with their expiration date precariously close, so today's main ingredient had no choice but to be chicken thighs.
Compared to the burger we'd had for lunch, there wasn't anything particularly special about it, but home cooking is often like that.
"It was delicious again today, Brother."
But my sweet little sister ate it happily again today.
As the one cooking, there was nothing more gratifying than her always eating well without being picky.
"I'll do the dishes."
"It's fine. You seem to have a lot to organize, so I'll do the dishes. There aren't many to do today anyway."
In fact, since I'd cooked everything in one pan, the dishes amounted to just two bowls and one pan.
"Then, it's not much of a repayment, but let me thank you for all your hard work today. Could you come to my room after you finish the dishes?"
"It won't even take five minutes."
"That's fine. I'll be done preparing by then."
Aria smiled a mysterious smile and headed to her room.
As predicted, the dishes didn't even take five minutes.
I dried my hands and headed to Aria's door.
"Aria, can I come in?"
When I knocked and called out, an answer came immediately from inside the room.
"Yes, you can come in."
When I opened the door, there was Aria in a swimsuit.
And not just any swimsuit—the one I'd liked most earlier in the day.
A straw hat that gave off a pure, elegant feeling.
A black bikini top and bottom with a mature feel.
And a semi-transparent sarong that looked luxurious while still provocatively revealing the bikini bottoms.
"How is it? Does it suit me?"
The answer didn't come out right away.
To be precise, I lost my wits for a moment and froze, unable to answer, as if my brain had lagged.
Aria giggled, as if my reaction was the best answer she could have asked for.
"Hehe, I'm glad you seem to like it, Brother."
"Honestly, I have mixed feelings."
"Why is that?"
"Because I want to show off how beautiful my little sister is to other people, but at the same time, I never want to show this side of you to other men."
The words just slipped out naturally.
What contradictory feelings. Wanting to show her off to others while also wanting to keep her all to myself.
And at the same time, I wondered if I was actually a jealous person.
Even while I kept telling myself she was just my little sister, when it came down to the important moments, I wanted to monopolize Aria like this.
"You don't need to worry. I belong only to you, Brother."
Aria came close and whispered in my ear.
Belonging only to me.
As if she'd seen right through my possessiveness, Aria pressed herself against me until our skin was almost touching.
"So mark me clearly, so everyone else knows too. Right here—a mark showing that I belong to you, Brother."
Aria pointed at her pale nape.
"I might fail to control my strength today."
"I don't mind if it hurts. As long as it's from you, Brother."
I pulled Aria into my arms.
Thanks to the revealing bikini, no matter where I held her, I could feel the softness of her skin.
I bent down and brought my face to Aria's nape.
The now-familiar scent of winter forest and flowers reached me.
"Hah...!"
Controlling my strength just enough not to draw blood or leave a scar, I bit down on Aria's nape.
A heated sigh escaped Aria's lips.
Somewhere between a scream and a moan, the pain was at just the right intensity for the brain to mistake it for pleasure.
Aria's grip on me tightened.
Last time, I'd tried to keep my tongue from touching her as much as possible in case my saliva grossed her out, but this time I didn't care about any of that.
Because this was, literally, marking.
The stronger the proof that Aria was mine, the better.
How long had we stayed like that?
I slowly pulled my mouth away.
Red bite marks were left on Aria's nape.
It was just short of drawing blood or leaving a scar, but the mark looked like it would still be there tomorrow.
"Hah, hah..."
Aria was looking at me with a dazed expression, as if the strength had drained from her eyes.
"Sorry. Did it hurt?"
"Rather than hurting, it's more like... my body feels all tingly..."
Aria was leaning against me in my arms, as if the strength had left her body.
I laid Aria back on the bed, almost toppling her over.
The straw hat slipped off and fell to the floor.
"Ah..."
Aria didn't resist.
As if to say I could do anything to her.
But a thread-thin sliver of reason still held me back from doing something I'd regret.
However, that was only the last barricade—it couldn't dampen my burning possessiveness in the slightest.
Suddenly, my eyes were drawn to the shopping bag sitting in the corner.
Inside were the various accessories we'd bought today, the ones that weren't swimsuits.
I picked up the collar from the shopping bag.
Then I approached Aria and slowly fastened the collar around her neck.
Aria only let out a heated sigh, offering no resistance.
The collar covered the bite mark I'd just left.
It didn't really matter.
I could just mark her somewhere else.
I grabbed both of Aria's wrists and restrained them.
Her smooth underarms came into view.
Without thinking, I pressed my tongue into that secret crevice.
"Hyah?!"
Aria screamed, apparently not expecting me to lick her armpit of all places.
"B-Brother. There...!"
"You don't like it?"
"No, it's not that I don't like it... Hnngh!"
It was a strange sensation.
I'd thought licking an armpit would taste salty, but actually doing it, both the scent and taste felt sweet.
"Tell me if you don't like it. I'll stop anytime."
"...Please."
"I can't hear you if you don't speak up."
I wasn't pretending not to hear—I genuinely hadn't heard her.
But Aria seemed to think I was pretending, and with an embarrassed expression, she raised her voice.
"Please... don't stop."
At those words, I pressed my tongue to the other armpit this time.
I'd never even considered that I might have this kind of fetish, so I was honestly quite surprised at myself too.
No, maybe it wasn't an armpit fetish—maybe it was simply because it was Aria's body.
The problem was that every part of her was beautiful and alluring.
Honestly, I felt like I could get excited by other parts too.
"Doesn't it tickle?"
"It tickled at first, but now it's all tingly, like when you bit my neck earlier, Brother..."
Aria was writhing and rubbing her thighs together.
At that sight, a little of my melting reason returned.
At this rate, I might cross a line I couldn't come back from.
But I could still turn back now.
I could just treat this as some intense physical affection, or a bit of fooling around, and end it here.
I let go of the collar. Then I placed my hand on Aria's cheek.
It was the moment I was about to say let's stop here.
"Slurp, slurp..."
Aria sucked on my thumb just like that.
Then she pulled her mouth away with a soft exhale and whispered.
"Are you going to stop, Brother...?"