The Pop-up Surprise
It was the third day of the pop-up store. On a rare weekend, Mom had left the house at the crack of dawn again.
"I'm heading out, Dad."
"Yeah, have a good one..."
Unlike Mom, I saw Dad off as he headed to work, even though it was the weekend. Chaeyu was still asleep.
Don't tell anyone else... okay?
Why had Mom told me not to mention that piece of clothing? She had probably worn it under her shirt again today. A lewd thought crossed my mind—if she’d been wearing the same thing for three days, wouldn’t it be soaked in her scent? And Mom’s scent was just so intoxicating.
"Oppa... did Dad leave...?"
"Yeah. He just walked out."
"Oh, really...?"
"Why?"
"Just... I wanted to say goodbye..."
"It's fine. He's not the type to dwell on things like that."
"Is he...?"
"Don't you do that when it's just the two of you on weekdays?"
"I do, but..."
"That's enough. He’s the kind of person who’d be happy with whatever you do."
"Really...?"
Dad had always talked about his daughter—about Chaeyu—quite often. Of course, his wishes were simple: he just wanted to be greeted by his daughter, or have a meal with her.
"Right. What do you talk about when you're with Dad?"
"Just... asking what he's doing today... saying goodbye... asking what he likes..."
"Sounds awkward just hearing about it."
"Yeah. It is awkward."
"It's okay. Dad doesn't care about that stuff. He probably doesn't even realize it's awkward."
"Really...?"
"Why? Do you want to get closer to him?"
"Isn't that obvious? We're family."
"Then... he’d probably be happy if you bought him a gift."
"Really?"
"Yeah. I haven't been able to do much for him."
Aside from household chores, I hadn't done anything for Dad. The most I’d done was buy him a 600,000 won wallet when I started working, and he was still using it. Other than that, I’d been using my own money to stock the house with supplies. Since Mom didn't say anything when she cooked, I assumed I was doing a good job.
"Then let's go pick out a gift for Dad."
"Shall we?"
"Then do you want to go to Pangyo? We can see Mom, too."
"See Mom...?"
Mom had told me not to tell anyone else. But since I wasn't the one who brought it up, I figured it didn't matter. "Sure. Whatever... let's go."
I’d wanted to see Mom anyway, so this worked out perfectly. She had strictly forbidden me from coming on Thursday, but if Chaeyu was the one suggesting it, maybe she wouldn't mind.
"Wait, aren't you working today? It's the weekend."
"Nope? Today is my day off. Our cafe lets us take at least two weekends off a month."
"That's a good place."
Because of the nature of cafes, they were usually busy on weekends and holidays, so the whole staff had to work. If they gave at least two days off, that meant it was a pretty decent place. That was what Chaeyu had told me.
"You're driving, right?"
"No. We have to take the subway. Mom took the car."
"Really? That's a shame."
Chaeyu puffed out her cheeks in disappointment and walked toward me.
"Then let's do it before we go."
"...Do what?"
"What do you think?"
Chaeyu stepped closer. I’d already guessed what she meant, so I didn't back away.
"Mmph... haa..."
As she stood on her tiptoes and pulled away, a thick string of saliva dripped down. Because I was so used to this life, I felt a secret anxiety—what if she did this while Mom was right in front of us? ...Though we were already doing it in secret anyway.
"We haven't been able to do it lately. Because you keep coming home with Mom."
"You were on the closing shift the day before yesterday."
"That's different..."
"Hurry up and touch me."
"Where..."
"Everywhere."
"......"
I was wearing clothes that could be changed anyway. It meant I could get them as dirty as I wanted.
"Why aren't you wearing a bra?"
My hand reached behind Chaeyu and toward her chest. Instead of the usual padding, I felt the immediate elasticity and softness of her breasts.
"I don't wear one when I sleep."
"Fair enough..."
Unless you were sleeping with someone else, most people found it uncomfortable to wear one to bed. Of course, there were times she went braless even when she was out.
"Ugh, haa..."
I couldn't see them, but I used my senses to find her nipples, rolling them between my fingers. Chaeyu’s cute moans tickled my ears.
"Ah, haa..."
Moaning, Chaeyu pressed her hips against me. I pushed my waist forward slightly, making my cock brush against her.
"But is that true?"
"...What is?"
"That you get wet when you kiss."
"Suddenly...?"
"Yeah. Just curious."
"I don't know... I haven't really talked about that with anyone."
"What about you?"
"I've only ever been with you, so I wouldn't know."
"Exactly. So, how is it when you're with me?"
"...Why don't you check for yourself?"
"......"
At Chaeyu’s provocation, I moved one of the hands that had been fondling her breasts downward. I slid past her twitching stomach and reached her dolphin shorts. I pried open the waistband and slipped my fingers inside. As expected, it was soaked; I could feel the dampness on my fingertips immediately.
"I guess it's true."
"It's because of you..."
"Sorry... not really."
"Ugh...!"
I pushed my finger into the crevice where her juices were flowing. Along with the slick sensation, I began to gently stimulate her G-spot.
"Ugh, haa..."
Chaeyu’s waist recoiled, pressing into my cock. The stimulation from the morning had already gotten to me, and I had no choice but to take off my pants.
"Op...pa..."
"Take off your pants."
"Mmm... okay!"
As soon as Chaeyu pulled down her pants and panties, I instinctively slapped her ass. Having fallen forward, Chaeyu grabbed the sofa to steady herself.
"Do you like getting hit first thing in the morning?"
"I hate it..."
"If you hate it, why are you sticking it out?"
"Because Oppa likes it...!?"
Of course, I liked hitting her. But the way her ass was trembling in front of me right now, it looked like she was desperate to be hit.
"Liar."
"Ugh..."
The sense of elation I felt doing this in the morning—it wasn't like I had been the one to suggest it, but the thought that I could do whatever I wanted with my younger sister dominated my brain. What was in front of me was an *onahole* in the form of a sister. An *onahole* that couldn't be compared to anything sold in an adult shop. After all, that was how our relationship had started.
"Wait a second. Let me get a condom."
"Mmm..."
I quickly put on a condom before my erection could subside. Chaeyu waited for me, still bent over. I laid down a towel so the juices flowing from her pussy wouldn't stain the floor.
"Ugh...!"
Just as I rubbed my glans against her labia, I thrust my cock inside. Her pussy, already shaped to fit me, couldn't quite handle how much harder I was in the morning.
"Ah, it hurts..."
"That's because you're so tight..."
"It's because you got bigger... ah."
I bent my knees to match her height, moving slowly at first before picking up the pace. As my movements grew faster, ripples ran across her buttocks, and the wet, slapping sounds grew louder.
"Ha, haa..."
"Ugh, ah, haa, ugh...!"
My cock, already sensitive from the morning, was nearing the point of no return. But I didn't slow down; instead, I thrust with everything I had until I was ready to finish.
"Haa... ugh..."
"Are you... going to...?"
"Yeah. I'm going to..."
"Finish inside... please..."
"Don't talk like you're actually asking me to finish inside..."
"Ah!"
At the moment of climax, I grabbed her heaving breasts tightly and thrust my hips as far as I could. I felt the warm sensation of my semen surging into her.
"Haa... haa..."
"Ugh..."
When I pulled out, there was a *pop* sound. I rubbed the remaining semen pooled on my glans onto Chaeyu’s ass, leaving a mark.
"...It hurts."
"Did it really hurt that much...?"
"Well, do you think I'm pretending to be in pain?"
"...Sorry."
Chaeyu complained while holding her waist. I hadn't realized it actually hurt. "Your ass is really sexy."
"...Pervert."
"Who started it... hey."
Until Chaeyu, who had gone into the bathroom on her own, finished washing up and came out, I had no choice but to wait with my cock still exposed.
"Wow... there are so many people."
"Tell me about it..."
As expected, the department store was much more crowded on the weekend than on a weekday. Morning, lunch, or dinner, it was packed without a break.
"Is that the place? Where Mom is?"
"Yeah. The line is huge again today."
"Maybe there's something special on the weekends."
"Aha..."
The pop-up store was lined with people, as expected. There were so many that I couldn't even catch a glimpse of Mom.
"Let's buy Dad's gift first."
"Yeah. What should we get him?"
"He has a wallet... hmm. Clothes?"
"What about a watch? Does he have one?"
"Do you have the money for a watch...? The basic ones start at over a million won."
"Ah... that's not going to work."
"Otherwise, buy him some dress shoes. Those would be nice."
"Oh! Shoes are great!"
As far as I knew, it had been five years since Dad started rotating between two pairs of dress shoes. Because he wouldn't buy new ones unless they were literally unwearable, he only bought them when I told him to.
"Should we buy them here?"
"Do you have the money?"
"I have enough to buy something for Dad."
"Don't push yourself too hard."
"Yeah."
Then again, I’d bought him things often in the past. Thinking back on how I’d bought them with my part-time job money back then... I felt a little guilty. It was only because I didn't feel the burden of being treated to things by pretending to be his older sister; if I’d known I was his son, I would have let him treat me once in a while.
"Oh. I like these. What size is Dad's foot?"
"270."
"Same as Oppa's."
"Yeah. Our builds are similar, too."
A pair of shoes caught Chaeyu’s eye. The price was 400,000 won. It wasn't too expensive, but it wasn't cheap either.
"Try them on once, Oppa."
"Me?"
"Yeah. You said you're the same as Dad."
"Sure."
I tried them on in Dad's stead, and they fit perfectly. Chaeyu didn't even hesitate and decided on these shoes right away.
"Thank you~ Have a nice day~"
"You're surprisingly thoughtful, you know."
"What?"
"You're buying a gift for Dad. Most people wouldn't bother."
"I mean... we're not just passing acquaintances, we're family. I should at least give him a gift. If it weren't for Dad, I wouldn't have met you, Oppa."
"What a filial daughter you are."
"Right?"
Chaeyu might talk about it being awkward, but deep down, she clearly thought of us as family. Dad probably knew that, too, which was why he didn't care. My case was a bit different, though.
"Maybe I should buy a gift for Mom, too."
"Right. Mom likes fashion and stuff."
"Well... she'll probably like it. She works in that field."
I wandered around to a few places to buy a gift for Mom as well. In the end, I bought a scarf she could use every day.
"That will be 315,000 won after the online mall coupon discount. Shall I process the payment?"
"Please put it on one payment."
350,000 won for just one scarf. It was expensive by my standards, but looking at the average price of this brand, it definitely wasn't overpriced. And since my daughter had gifted him expensive shoes, a son should at least give her a gift of this caliber.
"Are you going to give Mom the gift now?"
"No, I'm going to give it as a surprise later."
"Aha."
Now all that was left was to see Mom. There were still a lot of people, but since we had nothing but time, we decided to wait in line.
"Ah~ so they're collaborating with this place."
"Do you know what brand it is?"
"Yeah. It's an underwear and lingerie brand. The one I showed you a long time ago, Oppa. The see-through stuff where you can see everything."
"......Really?"
The see-through panties and bra that had turned me on so much I’d had sex twice after seeing them. So that was this brand.
"There's Mom."
"Where?"
"Over there. In front of the register."
"So it is."
Chaeyu found Mom before I did. I picked out some items as usual and snuck up in front of Mom.
"That will be 15,000 won, ple──ase?!"
"Hi, Mom."
"Wh-why are you here... I told you not to come..."
"......Chaeyu wanted to see you, so we came."
"Oh, Mom. Are you wearing something from here underneath, too?"
I think I finally understood why Mom had been so embarrassed. It was because the underwear was incredibly lewd. Now that Chaeyu had pointed it out, I could see it a little bit. Her nipple.