I Fucked My Mother-in-Law to Marry My Girlfriend

"Alright, alright, that's enough of this heartfelt reunion, Yeonji. It's time to get ready for school."

"O-oh, Mom? Okay!"

Yeonji, who had been nuzzling her face against my chest while we hugged, quickly pulled away, her face flushed with embarrassment at being caught by her mother. She hurried back to her room.

"Hehehe… First, you were hugging me, and now Yeonji… You really are a devil, Master♥"

"Ahem! More importantly, what am I supposed to do now?"

I cleared my throat, brushing off her teasing, and asked about my new life in this house. I needed to figure things out today.

"Well, breakfast will be ready soon, so head to the dining room I showed you yesterday."

"Got it."

Since this was a mansion, every room had a specific purpose, and meals were served in a dedicated dining room.

'It's going to take some time to get used to this…'

Having lived in a cramped studio apartment where everything was in one space, this sprawling mansion felt overwhelming. Still, I had to adapt—this was where Yeonji and I would live together after we got married.

'Suddenly, I'm not working… I have a house, somehow… and a fiancée… Isn't this everything I've ever wanted?'

I had enough money to never work again, a dream home, and the woman I wanted to spend my life with. Something felt a little off, but I'd achieved almost all my goals.

'Of course, my mother-in-law is an unexpected addition… No, I never even considered that.'

Training my mother-in-law as a slave was never part of my life plan, but somehow, it had become my top priority.

'I'm already getting used to her calling me Master…'

When we were alone, she naturally referred to me as "Master." It had been awkward at first, but after last night, when we'd crossed every boundary, the discomfort had faded significantly.

Growl

"Let's head to the dining room."

My mind was still a jumble, but I was starving after the intense activities of the previous night. I made my way to the dining room.

"Good morning, Juhyun."

"Good morning, Yeonhee."

Everyone except me was already gathered in the dining room: my mother-in-law, Yeonji, and Yeonhee. Despite there being only four of us, the table was enormous. I sat next to Yeonji, who made me feel most at ease, while Yeonhee served breakfast. We ate together, engaging in light conversation to ease the tension.

'Come to think of it, Yeonhee hasn't said much…'

Most of the conversation was between my mother-in-law, Yeonji, and me. I tried asking Yeonhee a few questions, but she only gave short, clipped answers.

"I'll excuse myself first."

Yeonhee, who had finished eating, stood up and left the table. My mother-in-law sighed softly.

"She's not usually like this… I think she's still a bit uncomfortable around you, son-in-law."

"Ah… I see…"

"Oppa is such a good person… Why doesn't Unnie like him?"

My mother-in-law explained that Yeonhee was acting colder than usual because she didn't approve of me. Yeonji pouted, clearly upset that her sister didn't share her feelings.

'Come to think of it, I still don't know much about Yeonhee…'

My mother-in-law and Yeonji were family, but Yeonhee was a secretary, not a daughter. It was a little strange that she was here with us, acting like part of the family, but I didn't pry—it felt too personal.

"Well, let's all get up now that we're done eating."

The atmosphere at the table had been dampened by Yeonhee's coldness, but I decided not to dwell on it. We'd have time to grow closer eventually.

Yeonji and Yeonhee left for university, leaving only my mother-in-law and me at home. Soon after, the staff who cleaned and managed the mansion arrived. They greeted us briefly before starting their work.

"They come every other day to manage the house, but they don't work on weekends. They mostly handle things on their own, so you don't need to interact with them unless you need something."

"Understood, Mother-in-law."

The housekeepers—about 50 of them—began cleaning and organizing in silence.

"Most of the essential furniture for your room will be delivered today, so you shouldn't have any major issues. We can go to the department store later to pick up anything else you need."

"Thank you, Mother-in-law…"

I rarely went to department stores, except for the occasional date with Yeonji. The thought of buying expensive furniture with my limited budget was daunting.

'My mother-in-law said she'd cover everything… I feel a bit guilty…'

For her, buying a few pieces of furniture was probably as trivial as buying a 500-won gumball from a vending machine. But for someone like me, who had no experience with wealth, it felt overwhelming.

"We'll head to the department store after lunch… Until then, let me tell you about Yeonhee."

"Yes, Mother-in-law."

I felt a twinge of nervousness as my mother-in-law finally prepared to explain Yeonhee's story. We moved to the living room.

...…

"Yeonhee… she's not my biological daughter, but I consider her as one."

"I figured as much, given how she interacts with Yeonji."

Someone who wasn't a daughter but was treated like one—I'd suspected there was a complicated backstory.

"When my husband and I were dating and engaged, we faced a lot of opposition from those around us."

"Because you were marrying the heir to the Choi Han Group?"

"Exactly… People said he'd 'play with me and throw me away'… that he didn't truly love me. At the time, I came from an ordinary family."

It sounded like a drama: a wealthy man falls for a commoner, and they marry despite the odds. Of course, the master-slave dynamic added a unique twist, but to outsiders, it must have seemed like a fairy tale.

The difference was that this wasn't a drama—it was real life. A wealthy man genuinely loved an ordinary woman and promised to marry her? Back then, people probably thought he was just toying with her.

"Of course, my husband and I were both serious, so we kept seeing each other despite the opposition… and eventually, my husband…"

"Ah…"

Her husband had died in an accident, leaving my mother-in-law to raise Yeonji, who was still in her womb at the time. She worked tirelessly and eventually inherited a majority stake in the Choi Han Group, securing her current lifestyle.

"There was one close friend who believed in me when everyone else opposed us… She said we'd make it work… that she knew our love was real…"

This friend was the only one who stood by her when her family, relatives, and most of her friends turned their backs.

"That friend had a daughter… and that's Yeonhee."

"Yeonhee? So, your friend…"

"She passed away… from an illness."

"…I see…"

The death of her only supporter left young Yeonhee alone in the world.

"At that time, I took in Yeonhee and raised her as my own… When she was young, she was close to Yeonji, who was born shortly after. But in middle school, Yeonhee found out she wasn't my biological daughter."

"Is that when your relationship changed?"

"Sigh… Yes… She's still legally my daughter, but learning the truth shocked her deeply. She gradually distanced herself and eventually decided to become a secretary instead of staying close as family."

Yeonhee, who had discovered the truth about her birth at a young age, chose to step back from her adoptive family. Instead, she took on the role of a secretary, maintaining a professional distance.

"I've thought about telling her to quit if she can't handle the job, but she's so good at it that I can't bring myself to say it…"

My mother-in-law wished Yeonhee would simply be a daughter like Yeonji, but she respected Yeonhee's decision to keep their relationship as it was.

"About a year ago, after Yeonji started dating you, son-in-law, Yeonhee became even more distant."

"Ouch… That's tough to hear."

Honestly, it's no secret that I'm far beneath Yeonji's social standing. She's the daughter of the hidden owner of one of the world's top companies, while I'm an orphan with no house, no car, and no prospects. It's no wonder Yeonhee disapproves of me being with someone like her sister.

"This has caused tension between Yeonhee and me for the past year, and we've grown even further apart… It's been a real struggle."

"I… see."

I hadn't done anything wrong, but I couldn't help feeling guilty for being the cause of this rift in my mother-in-law's family.

'I didn't do anything wrong, but… I still feel responsible…'

I hadn't caused this intentionally, but a family was being torn apart because of me. The situation felt both unfair and deeply regrettable.

"So, even if Yeonhee is cold to you, try reaching out to her… She'll come around eventually."

"I'll do my best."