disclaimer: dark themes, such a murder and psychopathy.

(I took as much smut out w/san in it that I could. there are still some suggestive/sexual parts, but I wanted to keep the idea of the storyline as close to the original as I could.)

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"Come on, Y/N. You know what'll happen when I find you!"

You stayed quiet in your hiding spot. You loved playing this game with San - he always had a surprise for you when he found you. You were in one of the cabinets this time, and you heard him walk by, then stop dangerously close to you. You heard him grab the handle to the cabinet, then the small door swung open, and you were faced with San.

"You know I don't like this game." San whispered. "I'm beginning to think you like my punishments."

You smiled and crawled out of the cabinet. "I do like your punishments."

"Really?"

You nodded as your hands found their way to his thighs. You leaned in close to his face, but he stopped you with an aggressive hand to your throat. You laughed as he made you stand up with him, then his other hand was making its way up your shirt.

"You won't like this one, Y/N."

"Is that a challenge, Choi San?"

He made eye contact with you and licked his lips. "It's a warning."

He turned you around and grabbed a handful of your hair, making you walk in front of him. He threw you down onto the couch and put his leg in between your thighs.

"Strip for me, baby."

You started to unbutton your pants, but then you had an idea. "Why don't we go put on a show for our guest?"

"I don't want him seeing you like that-"

"He's going to die anyways, San. Come on, it'll be fun. We've never gotten intimate in front of one of our kills before." You said. "It'll be torture for this guy, you know he wants me underneath him."

He nodded. "That's exactly why I don't want to do it."

"Then I'm not stripping for you. You'll have to rip my clothes off of me."

He sat back on the couch and smirked. "I've done it before, I'll do it again."

You rolled your eyes and stood up, heading for the basement. You took your shirt off as you went downstairs, San right behind you.

"If you won't touch me, maybe he'll get what he was hoping for the whole time." You said as you looked at the man tied up in the chair.

You were about to grab the back of the chair when San pushed you back and into the wall. His hand was around your throat again, seriously cutting off your airflow, but you didn't mind.

"You've been such a bad girl lately, maybe I'll just devour you in front of this guy." He growled. "Do you want that, princess?"

After you and San showed off and had your fun, your victim was clearly uncomfortable, but he couldn't take his eyes off of you. The way you were breathing was enough to get him off right there. You and San both got half dressed again, and you smirked as he grabbed some gloves off of the table and handed you your knife.

"What are you gonna do to him, San?" You asked.

He shrugged. "I don't know yet. You pick."

"Let me go first, then you can have him."

He nodded and helped you off the table, like the gentleman he was. You got down to your victims eye level and ran the blade up his arm, gently enough to where it didn't break skin. You went across his chest and down his stomach, and stopped right above his pelvis. You aggressively pushed the knife into him and he screamed out in pain. You pulled the knife out and stabbed him once more in the thigh, then you gave him up to San. You watched as San used his fists to finish the guy off, and you kicked your feet like a child getting a new stuffed animal.

Once the poor guy was dead, San grabbed your hand and pulled you upstairs. He kissed your temple and sat down on the couch with you.

"That was actually fun." San smiled. "I liked taking you, right there in front of him."

You laughed and laid your head on his shoulder. "We should definitely do that more often."

Yeseul gasped when she saw you, and pulled you into an empty hallway of the school. "What is up with that bruise on your neck, Y/N?"

"Oh, San-"

"Actually, I don't want to know."

You nodded. "Yeah, I don't think you do either."

"You and San have been together for a while now, but you're all anyone ever talks about still." Yeseul told you. "It's like everyone's obsessed with you guys."

You shrugged. "Some people can't mind their own business. I haven't even noticed, honestly."

The two of you started walking to class again, meeting up with San on the way. Yeseul was happy for you, but she felt like there was something you were keeping from her, and it made her stomach turn every time she thought about it. She could see this hint of something in your eyes sometimes, and she felt like whatever you were hiding from her was dark. Especially now that you were with San, it had gotten much more prominent.

During class, you couldn't focus. All you could think about was the previous nights kill and how desperately you wanted to do it again. San could tell by the way you were bouncing your leg that you were thinking about it, you always did that when you wanted to hunt for a new victim.

A phone going off brought you from your thoughts, and your teacher checked, since she had been following the investigation of the murders very closely. "They've found another body in the Han River."

The class started murmuring, but you and San just looked at each other. Yeseul caught this and that uneasy feeling settled into her stomach again.

After class, you and San were walking together, and you heard a couple of students talking about how a local was probably killing all of those people. You scoffed and started to walk towards them, but San caught your wrist and pulled you back to him.

"Are you crazy? Were you about to open your mouth?" San questioned.

"I am crazy, actually." You said. "And, they should know that a local didn't do this-"

"But they can't know that we're doing it, Y/N." He said, his voice low. "I think you're losing it."

You smiled. "I've already lost it, and so have you."

San looked at you for a moment with a straight face. He sighed and continued walking, so you did as well. You had different classes, the two of you separated, but Yeseul caught up with you.

"Hey, Y/N," she paused. "Is there something you're not telling me?"

You looked at her and shook your head. "Of course not. I tell you everything."

"I know. I just feel like there's something that you don't want to tell me, and I just want you to know that you can tell me if you want to."

You looked back in front of you and thought about it. You trusted Yeseul with your life, and you would never put her in harms way, and you knew San wouldn't either. If you told her, you'd put her in an impossible situation, and you couldn't do that. You knew she'd feel guilty knowing who killed those people but not being able to tell the authorities because it was her best friend.

"You know everything, Yeseul." You said. "Promise."

Yeseul wasn't convinced, not one bit. If there was one person who could tell when you were lying it would be her, and she could point it out every time. So, she decided to stop by your place.

She knocked, and you almost immediately answered, wiping something off of your face. "Is this a bad time?"

You shook your head. "No, no. Come in."

She stepped in and looked around as an odd smell took over her senses. She scrunched her nose and covered it with her sleeve, giving you a glance.

"Why does it smell like that?" She asked.

"We just had our monthly deep clean the house day. It's probably the chemicals."

That wasn't a complete lie. You and San did just bleach the basement earlier that morning, now that you had another guest occupying it.

"Where's San?"

"Finishing some cleaning in the basement." You sighed and tucked some hair behind your ear. "So, what brought you here?"

"I just wanted to see if you were okay, because you've been acting so strange lately. I'm worried about you, really, and I know you're lying to me about not hiding something."

You were about to open your mouth when San came out of the basement, breathing heavily. Yeseul tilted her head and looked at you, and you looked at San.

"Did those cleaning supplies kick your butt or something?" You laughed.

"Yeah, actually." San nodded. "Hey, Yeseul."

"Hi." Yeseul smiled kindly. "Okay, well I think I'm going to go."

"You don't want to stay for dinner?"

She looked between you and San, then shook her head. "Not tonight. Thank you, though."

You watched her walk out of the house and shut the door behind her. San locked it and walked up to you, placing a gentle hand on your waist.

"I think she knows too much." He whispered.

"She doesn't know anything-"

"She knows that something isn't right, and if you're not careful, she'll know." San said. "You need to do something."

"Like what? Kill her? I'm not killing my best friend, San."

He shrugged. "You'll have to if she finds out. I mean, who's more important, your 'best friend', or the man you kill with?"

"My best friend." You growled. "As much as I love you, my best friend will always come first."

He licked his lips as he slowly nodded. "Then I'll kill her myself."

He turned away from you, but you grabbed his arm and pulled him back. He faced you, and you grabbed the collar of his shirt.

"If you touch her, San," you paused. "You will never kill another person again. Am I understood?"

He smirked and grabbed your hand that was on his shirt. "I wouldn't hurt her, I know what she means to you. I just wanted to see you get all worked up. However, she can't know."

You gave him a look, telling him that you already knew that much. You walked towards the couch, but before you could even think about sitting down, San bent you over the back of it, his body right against yours.

"Let's try something else tonight, hm?"

"What's that?" You replied.

"Let's go down there," he bent down to your ear. "And I'll let them touch you."

You bit your lip and backed into San, earning a moan from him. "Let's go, then."

"Look at him," you whispered. "Even after chaining him to the chair, he's still aroused."

San hummed and looked over at you. "He wants you so bad."

"I know he does."

You started stripping, and San watched from behind carefully. You sauntered over to your next victim and let one of his arms free from the chains. You told him that he could touch you, so he started reaching for your sex, but San made a noise of dissatisfaction.

"Lick your fingers first," San said. "She's always wet for me but she probably won't be for you."

The man couldn't do it right, so San really had to show him how you liked it. "See how she's shaking?" San questioned. "If she's not shaking, you're not doing it right."

The man gulped and shook his head as San put his fingers in your mouth. "I can't."

San took his fingers out and you pouted at your victim, "Why not?!"

San nodded. "Fine with me."

San dragged you upstairs and made you get dressed again, making you pout once more. He crossed his arms and shrugged.

"What, Y/N? I don't like other people touching you."

"But that would have been so much fun!" You exclaimed. "Come on, San."

He sighed and grabbed your hand, helping you up off of the couch. "Maybe next time, but I'm just not ready."

Yeseul was very observant of you the next day. You looked anxious and unhappy, she even tried to hug you, but you flinched away from her. You said "sorry, it's not you", and kept walking.

In reality, you and San had killed off your previous victim and you were ready to find a new one. It was like an addiction that you needed to fulfill every day. San wanted to wait a couple of days, but you couldn't.

"San, please." You said as you stopped in front of your car after school. "Please, can we look for someone?"

"No, Y/N. I just want to spend time with you, without worrying about how we're going to dispose of a body." San said.

"I know, but after this one we can wait. I promise."

San sighed and went to the passenger side of your car. "Fine."

So later that night, you were out to find the perfect victim, and when he bumped into you and grabbed your waist, without a touch of sexual intent, you still wanted him as your next. You smiled and told him that it was fine, then you both ended up talking for a little while. With a little bit of coaxing, you talked him into going home with you.

When you walked through the front door with him, San immediately got up from the couch as you locked the door. Your next victim looked back at you with a confused expression.

"What's going on?" He asked.

"This will be fun, don't worry." You smiled. "What's your name?"

"Oh Joonho."

San gave you a weird look. "Why did you just ask what his name was?"

"I don't know." You shrugged. "It kind of slipped."

San took him down to the basement and chained him up, and you discussed what would be done with him when he came back upstairs. About an hour or so later, Yeseul came through the front door, frantic.

"Y/N, my brother is missing!"

You stood up and furrowed your eyebrows. "You have a brother?"

"I'll explain later, but you're the only person I can trust with this." She said.

"Okay," you paused. "What's his name?"

"Joonho."

Your lips parted slightly. There was no way to keep the cat in the bag on this one. You couldn't kill her brother, and you definitely couldn't let her know that you had him, but you also knew that San wouldn't let him out of the house alive.

"I'll help-"

You were cut off by a loud yell from the basement. Yeseul narrowed her eyes and listened to the string of incoherent screams, which she seemed to be making out just fine.

"Is there someone yelling "help me" in your basement, Y/N?" She asked.

You shook your head. "No."

She tilted her head and headed for the basement door, successfully opening it before San could get to her. You both rushed in after her to try and prevent her from seeing her brother tied up in the chair, but it was too late.

She was looking at her brother, eyes narrowed and expression confused. "Joonho?"

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