Secretly with Yeonji Behind My Mother-in-Law's Back
"Yeah, come on in."
"Hehe, coming in!"
Yeonji slipped quietly into my room. Watching her expression—so excited, like a child trying to pull off a prank behind their parents' backs—I couldn't help but find her truly innocent.
"Wow~ Oppa, there's so much more stuff in here than when you lived here before!"
"Y-yeah... I guess so. Even I'm seeing a lot of this for the first time..."
With the furniture I’d picked out at the department store and the pieces my mother-in-law had ordered arriving, the once-barren room had transformed into a proper, livable space.
'Come to think of it, there really is more furniture here than in the studio apartment I used to live in.'
It was just one of dozens of rooms in the mansion, and while the sheer scale of it compared to my old place felt a bit awkward, I was happy just to have a room that was truly my own.
"Oppa, the bed!~"
Thump.
Excited, Yeonji headed straight for the bed, diving onto it and rolling around in delight.
"Huh? But this bed... it looks exactly like Mom's, doesn't it?"
"I-is that so? My mother-in-law recommended it, so I just went with that..."
"Really? Mom's bed is super fluffy, so this should be great~"
For a split second, my conscience pricked me and I felt a pang of guilt, but Yeonji, oblivious to everything, just smiled brightly and buried her face in the duvet, clearly thrilled.
"Sniff... it doesn't smell like Oppa yet."
"That's because it's the first day we're using it."
Yeonji buried her face in the pillow, inhaling deeply.
'If we hadn't changed the furniture... that would've been dangerous.'
I had spent the night in this very room having rough sex with my mother-in-law. If we hadn't replaced the furniture, Yeonji might have caught the scent and figured it out.
Cold sweat trickled down my back, but I forced a relaxed expression and approached her.
"And you should be careful—if you're too loud, your mother might hear us."
"It's fine~ The walls in our house are pretty thick, so Mom won't hear our voices!"
'But the wall here is thin...'
Unlike the other walls, the one between my room and my mother-in-law's had a hidden door installed. Yeonji, unaware of how thin that specific wall was, assumed her mother wouldn't notice and spoke with ease.
'She’s probably already heard us.'
My mother-in-law had forbidden Yeonji from sleeping with me for the time being, but Yeonji had snuck in because she wanted to be with me. Under normal circumstances, I would have been overjoyed to hold her and spend time doing lewd things—if not full-on sex—but I held back, knowing that anything we did now would be heard by my mother-in-law.
"I love living with you, Oppa... Before, Yeonhee-unnie kept coming to pick me up, so I couldn't stay late."
"Yeah, that's true... Now we're in the same house all night long."
"Hehehe, that's right."
Yeonji hugged me, rubbing her face against my arm. Her face was full of a happy smile that she couldn't seem to hide.
"I'm going to stay with you all night tonight."
"Won't your mother find out? Instead of that, maybe you should go back to your room if it gets too late..."
"It's fine, I can just wake up early tomorrow morning and go back."
"O-oh, right."
Yeonji wasn't wrong, so I couldn't even bring myself to refuse.
'I can't even tell her the truth, this is a mess...'
"Do you hate being with me, Oppa?"
Seeing my lukewarm reaction, which was the opposite of what she expected, she looked at me with sad eyes.
"No way!! Do you have any idea how much I wanted to be with you, Yeonji!"
Squeeze.
"Oppa♥"
My head was a mess because of my mother-in-law, but there wasn't a shred of falsehood in my feelings for Yeonji. If it weren't for my mother-in-law, I would have wanted to ravish her right then and there. My love for the girl in my arms hadn't faded in the slightest; it was only growing stronger by the day.
'The more I feel this way, the guiltier I feel... but there are no other options.'
"Hmm... holding you like this makes me feel so good, Oppa♥"
"Y-Yeonji?"
We had spent an hour being lovey-dovey, and I had even considered just sleeping together, but—
Slide... slide...
"Oppa, you're... hard here♥"
I hadn't expected Yeonji to stroke my cock through my pants with such a lewd smile.
"Your mother is in the next room, can't you hold off for today?"
Even though we were alone in a room with the person I loved, I tried to restrain myself because my mother-in-law could hear everything from next door, but Yeonji's hand didn't stop.
"It's been a while since I touched yours♥... It's so big and hard♥"
Slide, slide, slide, slide.
"Ugh! Yeonji..."
Before I knew it, Yeonji had slipped her hand into my pants, grabbing and shaking my cock.
"You haven't done it since you came to our house, either... So I'll help you release it♥"
'I've been doing it with your mother every day, so I'm fine!'
I wanted to say that, but I wasn't stupid enough to let those words slip out.
Tap, tap, tap, tap.
"Oppa, your cock feels even bigger than before... Sniff♥ It even smells stronger♥"
'Was Yeonji always this lewd?'
Of course, when we were at the studio apartment, she would occasionally show this lewd side of herself by giving me handjobs, but she seemed different now.
"Actually, I masturbated before bed yesterday♥ I was imagining you coming to ravish me."
"Me?"
"Yeah... we're living together now... and I knew you liked doing this with me, so I was a little hopeful♥"
I had spent an unforgettable night with her mother, not Yeonji, but hearing that she had spent the night masturbating made my cock stiffen even more.
"Haa♥ It got even harder... Did you get excited hearing that I masturbated?"
".....Yeah...."
"Oppa, you're so lewd♥"
When I answered honestly, Yeonji laughed playfully. As she continued to grab and shake my cock without pause, she reminded me of her mother.
'Looking at her like this, they really are similar...'
I had thought the only similarities were their looks and bodies, but seeing Yeonji’s lewd smile, I realized they were quite alike in their lustfulness as well. It was enough to make me think of my mother-in-law.
"Should I do it with my mouth?"
"Yeah... do it. Suck it with your mouth, Yeonji."
"Okay♥"
Usually, we just rubbed our hands or pussies against my cock, but she didn't do much else. But the current Yeonji knelt down on her own, looked at my cock, and opened her mouth.
"It's been a while, Oppa's cock... Bon appétit♥ Haa-up♥"
"Umm... Yeonji, that feels good..."
Like a polite lady saying grace before a meal, she took the head of my cock into her mouth.
"Haa-up♥ *Slurp*♥ *Suck*♥ *Ugh*♥... Oppa, yours is so big, it won't all fit in my mouth♥ Haa-up♥"
She didn't have the techniques of a masochistic bitch like her mother, so she just sucked on the head while jerking me off with her hand.
'She’s lacking compared to her mother, but...'
"That's good, Yeonji... you're doing great."
"Haa-up♥ *Ugh*♥"
It felt a bit lacking compared to the lewd fellatio I’d experienced with her mother—who would greedily suck my cock, taking it deep into her throat without even breathing just to please her male—but perhaps because it was the person I loved, it felt good.
"I wanted to suck your cock like this yesterday, too♥ *Ugh*♥ *Slurp*♥ *Ugh*♥"
"You're good at this, my Yeonji..."
As I stroked her hair and praised her, she smiled with her eyes, still keeping my large cock in her mouth.
"From now on, I'll suck it for you often whenever you want, Oppa♥"
"Yeah... I'm counting on you."
"♥♥"
Yeonji, who seemed to have become even lewder than usual, was saying things she would have been too shy to say before, looking genuinely happy.
'I don't know why... but this isn't bad at all.'
Who would hate it when their girlfriend becomes lewd and wants to do lewd things? Seeing Yeonji sucking my cock with such a lewd expression, the thoughts of my mother-in-law began to fade, and my mind started to fill with the desire to do even lewder things with her.
"Yeonji, come here."
"Haat♥ Oppa♥"
I couldn't hold back any longer; I laid Yeonji down on the bed and began to strip her clothes off.
"You're acting so rough today, Oppa♥"
"Am I? Sorry... I couldn't help it."
"N-no... I like it when you're a little rough, Oppa...♥"
I had acted roughly because of the sudden surge of excitement, and while I was flustered, Yeonji was smiling as if she liked it.
"Do it more, Oppa♥"
"Yeonji!!"
I forgot that my mother-in-law might be listening in the next room and began to tear off Yeonji's clothes. I ripped her T-shirt off as if I were shredding it, pulled her skirt and panties down in one motion, and tore off her bra, tossing it aside.
"Haa♥... Haa♥... Haa♥..."
It was as if I were about to rape her, but Yeonji was smiling lewdly, fueled by her own excitement.
"Oppa♥... do it to me♥"
Slide.
Yeonji spread her legs, reaching out toward me with an ecstatic smile.
I could do it now.
Because of my large cock, I hadn't been able to fit into Yeonji's small pussy before, but now...
An impulse took over, the thought that I could force my way in and shove it into her small pussy.
Slide... squelch.
"Heeeeeeek! O-Oppa!"
"Yeonji, I..."
"I-it hurts......."
"Ah....."
As I tried to force my cock in, getting the head about a third of the way into her small pussy, tears began to stream from Yeonji's eyes.
"I-I'm sorry! I didn't mean to... are you okay?"
"Yeah... I'm okay... but it's still a little scary..."
"Yeah, I know... I'm sorry, Yeonji."
"Oppa♥...."
Flustered, I pulled my cock out immediately and hugged her, and Yeonji smiled weakly again.
"I'm sorry... I'm still..."
"No... let's take it slow, okay?"
"Yeah... thank you, Oppa."
I had almost forced myself into her as if I were actually raping her, but I barely managed to regain my reason and stop.
'Why am I like this? Ever since I did it with my mother-in-law, I've been getting more and more...'
I was startled by my own rough behavior, which had started to surface occasionally, but I had calmed down for now.
"Should we do it like we usually do, then?"
"Yeah, okay."
Squelch, squelch, squelch, squelch.
"Haat♥ Hnnng♥ Haa-ang♥ Oppa, that feels so good♥"
We did sumata, rubbing my cock against her pussy. The pleasure was far less intense, but the very fact that I was doing this with Yeonji felt good, and lewd moans leaked from her lips.
"If you're too loud, your mother might hear us."
"Hnnng♥... Then... cover my mouth, Oppa♥"
As Yeonji opened her mouth with a lewd smile, I opened my own and leaned in toward her.