Blood is a Promise

A White Christmas fic.

First published September 2021.

Youngjae x Eunsung, 7386 words.

Contains self-harm, suicide references, smut, blood play, knife play, sadomasochism.

Chapter 2: Eunsung

For the next few days, Eunsung ignores him. It’s the way she usually treats him, after all – it would be more comfortable to go on treating him that way. Never mind that she’s still carrying his knife around with her, the second big secret between them.

It’s hard for her to believe that she did what she did. That she could draw a knife along another person’s flesh. It’s one thing to cut yourself – it’s another to cut another person.

And yet can’t say she wouldn’t do it again.


She’s leaving the laundry room one night when he comes in, and it’s the expression on his face that decides her – only the usual mix of fear and hope, but it means something different now.

She lets him pass her, and she puts down her laundry basket while she watches him put his own washing on.

‘I guess you know how to get bloodstains out, huh,’ she says. Playing with her food. Has she always been like this? Maybe she has.

‘Why,’ he says, ‘are you going to stab me?’ He glances over his shoulder, in dread or anticipation.

‘Don’t sound so excited,’ she says. She crosses the room, perching on the machine beside his. ‘It’s just so hard to find anywhere to have a decent tryst.’

‘You and Park Mooyul managed.’ He finishes putting the machine on, and then he stands, eyeing her warily. Eunsung lifts an eyebrow at him.

‘I think you dropped something,’ she says.

‘What?’

‘Under the machine.’ Eunsung drops down on her hands and knees; Youngjae copies her, but he’s confused. He can be a bit slow, sometimes.

Trusting their bodies are blocking the cameras, Eunsung pulls the knife from her pocket, and she slices down the back of his thumb.

This time, Youngjae hardly squeaks – only his hand jerks a little, wanting to pull away. The blood wells up quickly, and Eunsung has to resist touching it.

‘Found it,’ she says instead, and she slips the knife back in her pocket and stands up. She feels giddy. Youngjae stays on the floor, and maybe her excitement is making him nervous, because he covers his injured hand with the other. Shields his blood from her sight.

‘Thanks for your help,’ he says – keeping up their act for the cameras.

‘Any time,’ she says. She goes to collect her own washing, and leaves him there to collect himself.

It’s strange, but she feels lighter than she did before. Like hurting Youngjae has taken a weight off her back. And maybe it has, because she doesn’t need to worry any more about whether she’ll do it again. She knows that she will.


After that, she hunts him down, again and again. Taking the seat next to his in study hall, or finding him in the break room on a quiet night – it’s not so different from carrying out an illicit romance after all. Only instead of holding hands, she cuts him. And he lets her.

Even if no-one picks up on what they’re doing, the fact they’re spending time together doesn’t go unnoticed. Mooyul sits beside her one lunchtime and says, ‘I heard you’ve been spending time with Jo Youngjae lately.’

He sounds serious, which makes it hard for Eunsung to answer seriously.

‘Don’t tell me you’re still trying to save me,’ she says.

‘Yu Eunsung.’ He pitches his voice lower. ‘He tried to get you killed.’

‘He didn’t succeed.’

‘Not because of him.’

It annoys Eunsung, that Mooyul is bringing this up. She knows she never told him what happened that afternoon. She can’t imagine Youngjae did, and Yoon Soo isn’t a possibility.

‘Did Lee Jaekyu tell you this?’

Mooyul nods.

‘I’d say you two are the ones who’ve grown close, don’t you think?’ She makes her voice dismissive. ‘If you can forgive him for us being there, then surely I can forgive Jo Youngjae shoving me under the bus.’

‘Can you?’

Trust Mooyul to ask the question she doesn’t know the answer to.

‘Park Mooyul,’ she says, ‘stop worrying about me.’ She lets her gaze drift across the room. She knows exactly where Youngjae is sitting, so she can avoid her eyes falling on him.

Does she forgive Youngjae? She’d like to think that what she’s enacting with him is some sort of punishment, but she knows that it’s not. It’s more that the darkness in Youngjae feeds the darkness in her. They could have gone their entire lives without knowing, but since they’ve been through what they’ve been through, there’s no way to unknow it.

‘I’m always going to worry about you,’ Mooyul says. ‘It’s not only you though.’

She looks back at him, sharply. ‘What’s that meant to mean?’

‘Jo Youngjae.’

Eunsung almost laughs when she realising – Mooyul’s not worried about what Youngjae might do to her, he’s worried about what she might do to him. He’s so close to knowing what’s going on. If only he could stretch his imagination a little further. He’s seen the scars on her wrists, but he would never imagine her inflicting them on another person. He still thinks too highly of her.

‘I’ll be careful,’ Eunsung says. She’s not sure, from Mooyul’s expression, that it’s the right answer.


Careful should mean pulling back, but Eunsung presses on.

She finds Youngjae in the hall after class that day. She enjoys the way he reacts with his whole body when he sees her – even though there are other people around and it’s not like she can do anything. He’s like a deer the moment it sees a wolf. He wants to run away, but he won’t. She wants to dismiss him, but she won’t.

No, that’s not true. She doesn’t even want to dismiss him any more.

He eyes her warily, pulling back from the people he’s been talking to.

‘Walk me to the library,’ she says. That’s all it takes for him to leave behind his ostensible friends and follow her. He’s gotten so obedient. But she won’t forget, ever, the look in his eyes when she learned who he’d named. The person with the most sins.

Only to him, she thinks.

‘Park Mooyul spoke to me,’ she says, as they walk. ‘He’s concerned about the time we’re spending together.’

She flashes him her teeth, but he doesn’t notice. She sees him move his hand to his wrist, protectively.

‘Relax,’ she says. ‘He doesn’t know what we’re doing.’ She drops her voice. ‘I wouldn’t let him know a thing like that.’

‘He’ll think it’s come true,’ Youngjae mumbles.

‘Huh? Jo Youngjae, did you say something?’

He just looks at her, darkly.

‘We can stop if you want,’ Eunsung says. They reach the library; she thinks he might leave her there. If he did ask her to stop, would she?

He doesn’t answer. 

‘Come on,’ she says, and she takes his arm and drags him into the library with her.

It’s not even that she’s thinking of taking the opportunity to do something. More that if people are going to notice them together, she may as well commit to it.


She never thought she’d end up being study buddies with Jo Youngjae. It’s because they can’t do anything else here, in this prison of a school. She can only hurt him in small doses. What she wants to do takes time and privacy, and they have neither.

If they did, maybe she could get it out her system.

‘Help me find something on the shelf,’ Eunsung says.

He follows her momentarily, down an empty aisle. She doesn’t even need to ask for him to roll up his sleeve for her. There between the stacks, their backs to the world, she slices along his forearm. He trembles but doesn’t flinch. She can feel the weight of his eyes upon her, and it warms her.

She wipes at the line of blood with her thumb, and then she puts her thumb in her mouth. She keeps her eyes on his.

He shudders, and he looks away from her. His arm falls.

‘When we get out of here,’ he says, ‘I’ll never see you again, right?’

‘Why, Youngjae, did you get bored already?’

His mouth makes the smile his eyes don’t; he cups his forearm in his hand.

‘I’m not talking about me,’ he says. He looks back at her, and Eunsung can see in his eyes, then, everything that he wants from her – that he wants to take, or that he wants taken from him.

She shouldn’t want him back. She wishes she could say she doesn’t want him back. It’s too much responsibility.

‘Maybe,’ she says, maybe she’ll never see him again. ‘Are you thinking of becoming my stalker?’

That rictus smile doesn’t drop. He’s not doing anything to stop the cut on his arm from bleeding, the blood forming a tear streak along his wrist to his palm. She takes his wrist in her hands.

‘I’ll file a restraining order,’ she says. ‘You won’t get within 200 metres of me.’

She folds her hand over the cut and presses down.

‘But I guess that won’t stop you,’ she says. ‘I’ll have to take up archery.’

‘Why stop there? Make it pistol shooting.’

She lets out a breath that’s almost laughter. She can imagine that too, even though they’ve both surely had enough of guns for one lifetime.

‘Well, I know where to aim,’ she says. She puts her free hand over his heart, makes a fist there.

It’s the closest they’ve ever been, she thinks.

‘Yu Eunsung,’ he says. He wets his lips. ‘Someone might come around.’

She stays like that a moment longer; then she thumps his chest and draws back.

‘Don’t be getting ideas,’ she says. She inspects the blood on her hand; Youngjae pulls his sleeve back down, and he leans against the shelves. Watching her.

‘Who really knows what the future will hold?’ she says, returning to his original question. ‘It’s a miracle we’re both alive today. I’m not making any promises, Jo Youngjae.’

‘I wasn’t asking –’ His voice is hot, but she cuts in coolly.

‘Either way,’ she says. ‘I’m not making any promises either way.’

She knows in her heart that she’s never going to let him go. She wants too much what he can give her – his pain and his desire both. She’s tasted it now.

Does he still hate her?

It hardly matters, does it? As long as he keeps allowing her to do this. As long as she keeps giving in.

‘Then I guess I’ll stalk you forever,’ Youngjae says. That’s a kind of promise too.