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It smells of heat, when Han Yoohyun opens the door.

Sweet, subtly floral—it’s a scent that he knows well, if more intense, heavier. It’s filling the air, making it hard to think straight as he shrugs off his jacket, setting his shoes next to Yoojin’s on the shoe rack. It smells of heat, his baser instincts are practically screaming. Like an omega. His omega.

Han Yoojin had presented as a beta when he was 17. Yoohyun has always had to press close to catch the faint trace of his hyung's scent—warm and inviting and safe, but nearly drowned out by his own. So even as his teeth ache with the urge to claim, he strides into the house with carefully measured steps. He won't let his work go to waste now.


There’s no answer, but he can hear the faint rustle of fabric from down the hallway. Yoojin is in their room—a pleased rumble bubbles up in Yoohyun's throat at the thought.

“Hyung,” he calls again. This time, there’s a muffled reply: a quiet groan. A drowsy call of what might be Yoohyun’s name. The smell grows thicker the closer he draws to their bedroom, almost stifling; it mixes with his own and makes his alpha instincts purr. “Hyung, are you alright?”

Yoojin is struggling to sit up when he pushes open the door. Their blankets are tangled together, a mess of sheets and pillows on the bed; one hand is clutching Yoohyun’s pillow to his side, the other rubbing the sleep from his eyes. He’s wearing one of Yoohyun’s shirts. It’s an omega’s natural instinct to surround themselves with familiar, comforting scents when their heat rolls around; Yoojin doesn’t even know it yet, but he’s following his instincts so well. His hyung is truly amazing, adapting so quickly. Yoohyun hurries over to his side, dropping to one knee by the bed.


“...Yoohyun-ah,” his hyung mumbles blearily. He smells so good, already reeking of desire. Like he’s asking for it. Yoohyun waits, the fabric of his pants bunching under his hands. He’s good at biding his time. “Mm… ‘s warm.”

Yoohyun presses the back of his hand to his hyung’s forehead—there’s a high flush in his cheeks, and it takes every shred of Yoohyun's waning self-control to ignore how Yoojin leans into the touch with a small, involuntary gasp.

“Hyung, you’re sick. I think you have a fever.”

Yoojin blinks at him slowly. Yoohyun cups his cheek, watching his eyelashes flutter. “You should get some rest, hyung. Do you need anything?”

“Thirsty, Yoohyun-ah…”

“I’ll get you some water, hyung. Here, lie down.” I’ll take care of you.

Drowsily, Yoojin lets Yoohyun position him back against the pillows, tucking their blankets snugly around him. So pliant, warm to the touch. There’s just a little longer until the worst of the heat hits. Yoohyun tells him to wait a moment, then slips out the door.

He strides down the hallway, a pill from his inventory already settling in the palm of his hand; with a smile, Yoohyun goes to get his hyung a glass of water.



Yoojin is burning, when he wakes again.

He’s hot all over, and mindlessly, he claws himself out of the suffocating shroud of blankets on the bed. Even the fabric of his shirt, damp with sweat, feels overwhelming; he wants to peel it off, preferably alongside a layer of his skin. His head is fuzzy with disorientation and a confused sort of fear: something's wrong, but he doesn’t know what. He doesn’t know what to do, he doesn’t know what’s happening—


Yoohyun’s voice is rough with sleep, softened by concern. A hand settles on Yoojin’s shoulder, grounding—Yoojin jerks towards it with a gasp, searching blindly for Yoohyun in the dark. His brother has always run hot, but his warm touch settles something in Yoojin, dampens the burning under his skin; Yoohyun is safe, familiar. His darling little brother. Yoohyun catches his hand in the dark, pressing it against his cheek.

“Hyung, what’s wrong?”

“Yoohyun,” Yoojin rasps. It comes out as a plea, but he doesn’t even know what he’s asking for. “Yoo—Yoohyun-ah.”

“Hyung, are you okay?” Yoohyun pushes him gently onto his back, his features indistinct in the dim light of their room. Yoojin reaches for him again, tangling his fingers in the fabric of his collar and sighing at the meager relief the contact brings, heart stuttering in his chest as Yoohyun brushes the damp hair from his forehead.

"'s warm," he complains softly.

There’s a moment of silence, and then Yoohyun is nosing at his neck, the solid warmth of his body much closer. Without thinking Yoojin drops his head back against the pillows, baring his throat, and Yoohyun makes a sound not unlike a growl deep in his chest. Yoojin’s stomach clenches, the sharp throb of arousal suddenly making itself known: he’s so hard it hurts. It’s dizzying. He's burning up. Something's missing. Yoohyun inhales, so close that his lips brush Yoojin’s skin.



“You’re in heat.”

For a second, Yoojin feels a brief but startling clarity: that’s not right. That can’t be right.

“I‘m not. I can’t be?”

Yoohyun touches his face, turns his head, examining him; in the pale moonlight, Yoojin can just make out the dark pools of his eyes, the furrow of his brow. His hand brushes Yoojin's jaw, tipping his chin upward, fingers bracketing his throat; Yoojin's stomach twists again, thighs squeezing together against the wave of want that shoots through him. There's something dripping down the cleft of his ass, making a wet spot under his hips on the sheets. Yoohyun’s scent, all around him.

“I, I’m a beta. I can’t be…”

The regression wouldn’t have. It couldn’t affect something like this, right. Yoojin was a late bloomer, but he’d still presented years before the System appeared. Weakly, he repeats, “that’s impossible.”

Yoohyun settles a hand at his knee, pushing his legs apart. Dazed, Yoojin lets him trail his touch, burning, burning, up his thigh to his waistband. “Should I check for you then, hyung? Even though I can smell it on you.”


Yoohyun’s hand slips into his pajama pants, cupping his ass for a moment. Yoojin whines at the touch, hips bucking upwards as he tries desperately to draw Yoohyun closer. This isn't right. This shouldn’t be happening.

“Like this.”

Yoohyun smells so good. His scent is usually faint, at least to Yoojin; the combination of Yoojin’s status as a beta and his Fear Resistance makes him immune to most pheromones, an extension of being immune to posturing. But right now he can smell Yoohyun so clearly. He fills his senses with warm spices, woodsmoke, something like flowers in bloom under everything else, a scent he knows they share. Yoojin buries his nose in Yoohyun’s neck and inhales, only the last shreds of his remaining sanity keeping him from licking at Yoohyun’s skin. Yoohyun’s fingers slide between his cheeks, rubbing against his hole; Yoojin whimpers, spreading his legs to let him closer. It feels good to be under him like this. Safe, protected. Yoohyun gives him another pleased growl, and Yoojin preens.

“Good, hyung,” Yoohyun murmurs, and then. “See. You’re wet.”

“Ah, huh?”

A finger circles his hole. Yoohyun says again, “You’re wet, hyung. And your hole is so soft, like it's trying to swallow my finger.”

“W-wait, Yoohyun—"

Without warning, two fingers slip inside. Yoojin's entire body flinches at the foreign sensation, his mouth falling open; there's no stretch, no faint discomfort. It's beyond feeling good—it feels right, settling the dull, confusing ache inside of him. But Yoohyun doesn’t do anything else, just presses his fingers into Yoojin’s walls, reaching deeper than Yoojin ever can, before drawing them back out. Yoojin makes some sort of noise, a sound he barely recognizes as being his own, and Yoohyun hums at him again, reassuring.

“Look, hyung.” His fingers are glistening in the faint moonlight. “Slick. I told you, you’re in heat.” He rubs them together, a pleased smile on his lips—then, in front of Yoojin’s mortified eyes, he sticks them in his own mouth.

Yoojin squeaks. “Yoohyun!”

Yoohyun licks his lips, swiping his tongue between his digits as if he doesn’t want to leave a single trace. “You taste good, hyung. You smell good too, you know?”

Yoojin's cheeks are burning, but he can't tear his gaze away from Yoohyun's. “Yoohyun-ah, you shouldn’t, something like that…"

“But it hurts, right, hyung?” Yoohyun’s hands return to Yoojin’s waistband, lifting his hips to pull his pyjama pants off. Yoojin arches into it, chasing the feeling of Yoohyun’s bare skin against his. “Let me help you.”

Yoojin shakes his head, squeezing his eyes shut. “You, you can’t.”

Hyung,” Yoohyun says plaintively, a hint of a whine. He grasps Yoojin’s knees, spreading his legs further; his fingers dig into the flesh of Yoojin’s thighs, just shy of painful. “You smell so good, hyung, please don't ask me to hold back.” His fingers return to Yoojin’s hole, stroking the delicate skin there.

“You can’t.”

“I wanna taste you, hyung, please,” Yoohyun presses three fingers inside this time, and Yoojin’s body takes them eagerly; Yoojin can hear his slick squelching between them as Yoohyun thrusts, dragging his fingers against his walls, searching. “You’re so hot inside, hyung.”

“Stop, Yoohyu—n!” Yoojin thrashes, hands flying up to cover his face at the sudden overwhelming pleasure that shoots up his spine—Yoohyun tuts at him, prying his hands away from his overheated skin.

“Don’t hide from me, hyung,” he touches his lips to Yoojin’s forehead, trailing them to his temple, then down his cheek. “You’re burning up.”

“Please, stop—”

“Are you sure you want me to?” Yoohyun asks him gently. “See, hyung, you’re leaking here, too.” Yoohyun presses a finger to the underside of his cock, making his dick twitch—Yoojin keens, arching into his touch. His hands tangle uselessly in the sheets as Yoohyun continues. “I can help you, hyung, I'll make you feel good.”

“Yoohyun, Yoohyun—"

“Yes, hyung,” his scent floods the room, blurring Yoojin’s senses again—warm, familiar, safe. Yoojin can feel the rush of slick around Yoohyun’s fingers, still stroking him inside. Suddenly, he wants it more than anything, needs it—Yoohyun inside of him, filling him up.

Alpha, please.”

Yoohyun goes perfectly, frighteningly still over him. Yoojin is completely caged in by his body, his scent; he tugs at the short, curling hairs at the nape of his neck and begs again, “Alpha.”

Yoohyun’s fingers leave his hole, making him gasp out a whine. “Tell me what you need, hyung,” he says, voice strained. Yoojin pulls him closer, giving into temptation and swiping his tongue over the strained tendon in his neck, chasing the taste of his skin. Yoohyun snarls, jerking in his grasp, teeth bared, before he remembers himself and stops.


“Touch me, Alpha, please—”

In the next second, Yoohyun is flipping him over. His weight settles on Yoojin’s back, pinning him down; Yoojin’s hips twitch into the sheets, desperate for relief, before Yoohyun’s hand on his neck stops him. “Alpha,” he complains into his pillowcase. Yoohyun shushes him soothingly, one broad palm slipping under his pajama top, hot against his skin—Yoojin shudders as his touch drags up his spine, raising his arms and letting Yoohyun pull the shirt off.

“Good, hyung,” Yoohyun murmurs. Yoojin whines, trembling as he trails his hands back down towards his waist. “Lift your hips, hyung, like that, perfect."

Yoojin shakily gets his knees under himself, whining when Yoohyun’s warmth presses down on his back. Yoohyun shushes him again, pressing a kiss to the top of his spine. "Hyung, let me take care of you."

Yoojin makes a mangled sound of agreement, canting his hips; Yoohyun laughs quietly and digs his fingers—gently—into the flesh of his ass.

“Look at you, hyung. You were made for this, I knew it.” Yoojin can’t help the clench of his hole at Yoohyun’s words, feeling the slick still dripping out of him. “You’re so wet down here. I only put three fingers in, but it’s so loose I think I could just fuck you right now.”

“Please,” Yoojin mewls. He presses his shoulders into the mattress, spreads his legs, arches his back—distantly, it registers in the last tiny coherent part of his brain that he’s presenting. Yoohyun makes that pleased growling noise again, and then he’s pressing his cock to the curve of Yoojin’s ass. Yoojin lets out a small, desperate gasp, his hips bucking backwards, but any other attempts at movement are halted by Yoohyun’s hand on his neck, shoving his face into the pillows.

“Hyung,” he says gently. “I said, let me take care of you.”

Yoojin starts making a muffled complaint, only to cut off into silence as Yoohyun’s cock begins pushing inside. It’s big, bigger than he’d felt through the thin fabric of their pants. Even with his slick easing the way, the stretch aches—Yoojin forgets how to breathe as Yoohyun forces his way deeper inside, shoving the air from his lungs with the sheer size of it. Suddenly, he can’t bring himself to feel embarrassed about what Yoohyun had said: he is made for this, this is good, this is right, being filled so completely.

Yoojin’s entire brain feels blank by the time Yoohyun is fully seated inside of him, mindless save for the weight of his brother’s cock, the warmth of his skin. Yoohyun noses at his ear, nipping at the lobe; Yoojin gives him a vacant whine, pinned in place.

“So good for me, hyung,” he murmurs, and Yoojin shivers. “You took it all so well, hyung, you’re perfect.”

“...Alpha,” Yoojin manages to slur. Yoohyun runs a hand through his hair.

“Mm, hyung.”

“Fuck me, please?”

Yoohyun laughs again, a noise Yoojin can feel rumbling along his back. “Yes, hyung.”

Yoojin’s voice cracks embarrassingly on a moan as Yoohyun draws away slowly, clenching instinctively on his shaft. That unfamiliar, distressing emptiness only lasts a moment before Yoohyun is thrusting back into him, hard enough to send the bedframe rattling against the wall. Yoojin lets out a strangled cry, the noise turning into another moan when Yoohyun repeats the action.

“Ha—nh, Alpha—!” Yoohyun grinds their hips together, hands bruising around his waist, and Yoojin screams when his cock rubs against his prostate, vision whiting out for a second before he manages to refocus. His thighs shake with the stimulation, dick dripping onto the sheets as Yoohyun thrusts shallowly against that spot.

“Here?” Yoojin writhes, hands fisting in the blankets. “Does it feel good, hyung?”

Yoojin buries his face in the pillow, feeling the damp mess of his own spit smearing across his skin. He can’t do anything but moan wordlessly, gut coiling tighter and tighter—he’s so close that it hurts. The thought of that burning heat finally abating makes him twitch his hips backwards, fucking himself on Yoohyun’s cock—the tip drags across his prostate again, and he shudders at the white-hot pleasure that strikes through him. He’s so close.

A firm grip prevents him from moving any more. Yoojin whines, squirming as best he can; all he manages is a laugh from Yoohyun above him.

“Hyung,” Yoohyun calls gently. Yoojin pants for breath, his quickly-approaching orgasm suddenly pulling short.

No,” he sobs, reaching for his cock; Yoohyun snags his wrist before he can get a hand on himself. Then he’s moving Yoojin with ease, pulling him until he’s propped upright in Yoohyun’s lap, the new position forcing him impossibly deeper. Yoojin mewls, writhing in place. “No, no—”

“Hyung,” Yoohyun says again, gentle even as he lifts Yoojin up. Yoojin scrabbles at his arms, nails dragging across his skin and clenching uselessly down on his cock, trying to keep him inside.

“Let, let me cum,” he begs. “Plea—se, please—”

Yoohyun presses his lips sweetly to the side of Yoojin’s face. “I asked you a question, hyung,” he purrs. Yoojin whines again, struggling against his vice grip. “You just have to answer and I’ll let you cum.”

When it becomes clear that his cruel little brother really isn’t going to budge, Yoojin forces his dazed mind into motion, trying to remember what it was Yoohyun had been saying, over the sound of his own cries. Yoohyun presses another kiss to his cheek, then trails more kisses down the side of his neck.

“...Alpha,” Yoojin starts, and then, “Yoohyun. Yoohyun-ah, feels good.”

Yoohyun moans, hips jerking. Yoojin almost laughs—this cute brat—but before he can Yoohyun is shoving him down onto the sheets again, pulling out and slamming back into him with force enough to bruise. Yoojin’s words break off into desperate cries as Yoohyun keeps fucking him like that, hard and deep, knocking whatever thoughts he’d managed to form from his head. All it takes is a few more thrusts before his orgasm crashes over him with the force of a lightning strike, his vision whiting out as Yoohyun fucks him through the waves of pleasure.

“Yoo—Yoohyun,” Yoojin manages, keening. The burn has waned, but he knows what he needs now. Yoohyun scrapes his teeth across the back of his neck, jaw clicking shut by Yoojin’s ear a moment later as he restrains himself once more.

“Sorry,” he growls, rocking his hips against Yoojin’s. “Hyung, ‘m close, just let me—”

Yoojin chokes on an overstimulated moan, clawing at the sheets; his dick twitches weakly, still leaking onto the sheets. “Yoohyun—”

“Sorry,” he rasps. “F—fuck, hyung, sorry, please, just let me, just let me use you for a bit, I'm sorry—”

Alpha,” Yoojin snaps with all the force he can muster. “Knot me, please.”

Yoohyun’s breath actually halts in his chest for a moment, before he moans, a desperate, wrecked noise; his next thrusts are messy, obviously chasing his own pleasure now. Yoojin can feel the base of his cock swelling, shoving past his rim, the knot thickening—a thrill shoots through him at the thought of being plugged up by it, Yoohyun’s cock spitting into him, being held under his little brother’s body so securely.

“Hyung,” Yoohyun moans into his skin, “hyung, hyung—”

His hips stutter, the fat knot pressing against Yoojin’s sore entrance; Yoohyun snarls and then bears down, shoving Yoojin’s hips into the mattress until his knot pushes past the ring of muscle. Yoojin might have screamed—he can’t tell, because Yoohyun grinds his knot directly into his prostate twice before he’s cumming, liquid heat flooding into Yoojin’s body. Yoojin clenches down on him—so big, filling him up just right—and Yoohyun’s hips twitch again, his knot tugging on Yoojin’s rim.

“Fuck, hyung,” he slurs, before a warm, broad palm grinds against Yoojin’s cock. Yoojin thrashes, mouth falling open as Yoohyun jerks him off, fingers tightening around the head of his dick—when he cums, this time, all he registers is blinding pleasure before his world darkens to black.



“It’s a rare case, but not unheard of,” the doctor says. She scribbles something onto a prescription notepad, sliding it across the desk towards Yoojin a moment later. “Take one daily, preferably before bed, for three months. Your heats and pheromones should settle by then, and you can see if you want to go on suppressants. There aren’t a wide variety that work around Poison Resistance skills, though, so you may have to consider alternative options.”

Yoojin nods, pocketing the prescription. She gives him a kindly smile. “Did you have any other questions?”

“No,” he says, at the same time that Yoohyun says, “yes.”

Yoojin glances up at him, and Yoohyun squeezes his shoulder reassuringly.

“You can go schedule your next appointment,” he says. “I’ll be right out.”

Yoojin nods and rises from the chair, bidding the doctor goodbye. The door clicks shut behind him, his footsteps heading down the hallway; they fade into silence as Yoohyun turns to the doctor, still wearing her gentle smile.

“It seems that the treatment was a success,” she comments. “I’m glad. It’s not a one hundred percent success rate, like I said. He hasn’t had any adverse reactions to being knotted?”

“No,” Yoohyun replies shortly. “When is it that I can mark him?”

“You’re eager,” she admonishes. “Three months for his cycles to even out, and then wait out his first heat after that.” Yoohyun dips his head. “You’re very dedicated. It can’t have been easy, especially since the process takes so long.”

Yoohyun pauses at the entryway, one hand on the doorknob. “Well,” he says, something that could be a smile on his lips. “I’ve been waiting for a long time already, after all.”