Chapter 4 – 1. The Reason Why My Sister Next Door Came to Live in My House (1)

Going back in time, it was around last year, when Se-ha did not live in Si-un’s house yet and was just “Her older sister next door.” At this time, Si-un’s father, Lee Do-hyeon, and his mother, Joo A-young, were still a married couple who had not divorced, and Do-hyeon had already been working as a professor at S University since then.
Then one day, it happened when Do-hyeon was having sex with a new female graduate student who had joined his lab in her professor’s office.

– Tiroling~♪ –

“Hmm?”

When her cell phone rings, Do-hyeon turns his head to the cell phone a little away. But now, on top of him sitting on the sofa, Siyoung, a new graduate student, has taken off her skirt and panties, leaving only her lower body naked, making it difficult for her to go to pick up her cell phone.

‘Well, I guess I can watch it later.’

– Tsk~ Tsk~ Tsk~ Tsk~ –

“Huh! Sigh! Sigh! Sigh! “Wow!”

Si-young, who is now on top of Do-hyeon, is not her virgin, but there is some awkwardness and hesitation in her movements, as if she does not have much experience herself. So, she helped Do-hyeon hold both of Si-young’s pubic bones and repeatedly pressed them down on his penis. Judging by her excellent response, it appears that she has enough talent.
In fact, the reason I had her take off her clothes from the waist down and leave her top and socks on was to be considerate because she was still embarrassed, but that shyness had already disappeared as if dry ice had evaporated, and she could now be heard outside of her professor’s office.

“Sigh! Professor! “I’m weird, this is my first time doing something like this, and I think I’m going crazy!”

“Okay, feel free to go crazy. That way we can get to know each other better.”

“Tsk… Yes! Ugh! Sigh! Ugh!?”

Since we are now in a relationship that will last for several years, it is clear that understanding each other deeply will help us work together in the future. Of course, this absolutely does not mean that Do-hyeon used his position to force this sex. When work at the lab was over today, she came to Do-hyeon and said that she wanted to leave her body to him, and it was Si-young who pulled off her skirt.
In that case, it would be the responsibility of the senior and advisor to respond to the spirit of inquiry of younger students who have worked hard to gain courage.

“Siyoung, show me all your embarrassing side. And trust me completely and entrust yourself to me.”

“Tsk… Yes! Oh! Ugh!”

– Ouch! –

As Siyoung grits her teeth and tightens her vagina, Siyoung’s sincerity is conveyed to Dohyeon, even though it is beyond the condom. And before she knew it, Siyoung had begun to shake off her waist. The thick clothes she was wearing only confined the heat she was giving off.

‘Well, this looks good in its own way.’

Do-hyeon also liked Si-young’s fresh outfit with only her bottoms on and socks on, but if he wants to see it, he can always ask for it next time. So, to change her position, Do-hyeon lifts Si-young’s body with their genitals connected and slams into her a few times. Then, he lays her on her side on the sofa and asks for her permission to take off her top and socks.

“Then I can be completely naked now, right?”

“Yes, Professor. No, Mr. Lee Do-hyun. Please take a look at all of Choi Si-young’s body. “Everything, even the folds of the anus!”

“Great! That’s it.”

In response to Siyoung’s honest confession, Dohyun immediately skillfully removes Siyoung’s clothes and throws them to the side. Then he becomes naked and begins to move his penis again.

“Heh! Hehe! Hehe! Heh!”

“Hugh! Sssss… Whaaaaa!”

“Tsk… Huh?”

However, although Do-hyeon did not specifically intend to do so, in the process of changing his position, he realizes that his cell phone, which was far away earlier, has moved to a place where he can reach it when he extends his hand. And to control the speed of ejaculation, I slow down the tempo for a moment and fuck slowly while picking up my phone and checking messages.

– From Wife: Are you late today? –

“Hmm?”

Do-hyeon sees this and tries to reply, but since he is massaging Si-young’s breasts with one hand, it is annoying to do so with one hand, so he just calls. And her wife, Ayoung, must have been waiting and as soon as the signal came, she answered the phone.

“Oh, what happened?”

“Are you done with work yet?”

“I’m done with work, but I’m currently training a new child.”

“Ugh! Huh! Tsk… Sigh! Sigh… Professor! Mr. Dohyun!!!”

“Yes, I understand.”

Si-young’s threatening voice is relayed to A-young through the phone, but she is not particularly surprised because her wife, A-young, has already accepted and allowed Do-hyeon to teach the students. But he asks what happens next if he has anything else to say.

“Then will it take long?”

“I don’t think it will be that late, but why? “What’s going on at home?”

“No, I just have something to talk about.”

“What happened?”

“It’s a bit awkward to talk on the phone… I’ll see you later.”

“Okay, see you later.”

– Drop –

“…”

The intuition that Do-hyeon and A-young had accumulated over the decades of living as a couple was sending a warning signal, telling them that something was not normal. So he remained silent for a moment, and Si-young, who was under her, asked with her tear-filled eyes.

“Professor?”

“Oh, sorry. Then let’s go right back.”

“Yes… Ik!? Haaaaa!”

– Boom! Puck! Puck! Puck! Puck! Puck! Puck! Puck! –

Do-hyeon, curious about what’s going on at home, picks up the pace and quickly begins to thrust into Si-young. And as if even that was tantalizing, he changed the position again, made Siyoung lie face down, and rammed his penis into her junior stomach as if cutting out her uterus. Siyoung was swept away by the sudden explosion of pleasure, shedding tears, saliva, and snot, and crying out loud.

“Evil! Argh! Ugh! “Uuuuuck!”

– Crunch~ Crunch~ Crunch~ Crunch~ –

And as they continued to fuck so furiously for a few more minutes, Dohyeon clenched his teeth and screamed.

“Siyoung, let’s go then!”

“No… I’m already gone… Haaaaa!”

It was like that. Si-young had already been leaving for a few minutes, but Do-hyeon didn’t pay attention and kept poking her, so she kept going again and again, becoming completely speechless for a long time. But Do-hyeon doesn’t care, and he selfishly continues to rub his waist until he is satisfied.

“Sigh! Hmm! Pfft!”

– Jump up! Jump up! Jump up! Jump up! –

“A billion… A billion… Huh…”

When Do-hyeon finished ejaculating and pulled out his penis, Si-young fell down on the sofa, her body convulsing and even slightly urinating. Seeing that, Do-hyeon massages Si-young’s butt as a plaything, slaps it, and rubs it again and asks.

– Bang! Phut! –

“Huh!”

“Are you okay? “Can you stand up?”

“No… Wait… Just wait like this…”

“Okay, okay.”

After checking Siyoung’s condition, Dohyeon removes the condom filled with the semen he just ejaculated from his penis, holds it upside down, and squeezes out and sprays the large amount of semen inside onto Siyoung’s sweat-soaked back.

– Rumbling~ Rumbling~ –

“Huh!”

As Siyoung reacts sensitively to the hot sensation of semen that has not yet cooled down, Dohyeon spreads his semen evenly on Siyoung’s back with both hands, like applying suntan oil. Then, the feeling of them seeping into her skin increased the amount of liquid Siyoung was choking on a little, and Dohyun pulled out a tissue and wiped both of his hands, then threw the tissue and the moist condom he had just used on Siyoung’s body and said:

– Clap! Clap! –

“Then Siyoung, take a break and when you feel better, clean and organize here and then go back. Please.”

“Ha, eh, armpit… Gasahani…”

Do-hyeon gives Si-young, who has trouble speaking due to a stuck tongue, some time to catch her breath, and he gets dressed first and leaves the professor’s office. And as I walk down the hallway, I can hear other professors here and there also working hard to teach. Normally, I would participate together, but today I head straight home.

Moments later, when Do-hyeon arrives home, his wife, A-young, greets him. However, when her son Si-woon is not seen, Do-hyeon asks.

“What about Siwoon?”

“I went to Jinseok’s house to play with Seha.”

“Hmm.”

Jinseok refers to Park Jinseok, Seha’s father, and Dohyeon, and he has been best friends since they were students. Because of that connection, he still lives right next door, and the children have been like siblings since they were born.
So, it was common for Si-woon to go next door to play with Se-ha, but Do-hyeon felt that A-young had prompted it just today. Perhaps it is because of the story that needs to be told from now on. And when Do-hyeon entered the house and saw A-young’s serious face, he immediately knew what the story was about.

“Then would you like to take a shower? Or eat first?”

“No, let’s start with that story.”

“…”

At Do-hyeon’s words, A-young smiles bitterly without saying a word. She knows Do-hyeon well just as Do-hyeon knows A-young, so she probably knows that her husband has already realized what she wants to say.
But even if she knew, it was something that was difficult to say out of Ayoung’s mouth. So, when Ayoung doesn’t say anything for a while as they sit across from each other on the sofa in the living room, Dohyeon breaks the momentary silence and opens her mouth first.

“Do you want me to divorce you?”

“… I’m sorry.”

Instead of answering, Do-hyeon lowered her head in apology and realized that the couple’s wedding ring was already missing from the fourth finger of A-young’s left hand.