Chapter Text
Alastor had always hated the concept of animal instincts. Which was ironic, considering he was an Alpha—the pinnacle of them. The radio demon prided himself on control. He wasn’t some mindless beast ruled by scent and heat. But of course, his time of the year was always so strong compared to other Alpha's, and because of that, he couldn't use rut suppressant like others could.
When Lucifer first came into the hotel, the real reason Alastor despised him wasn’t just the arrogance or the way he carried himself like he owned the place—though that certainly didn’t help. No, the real problem was scent. Lucifer smelled like honeyed apples and cinnamon warmth, a sweetness that clung to the air and burrowed under Alastor’s skin like an itch he couldn’t scratch. Worse, it wasn’t just any scent—it was an Omega’s scent.
There weren't many Omega's in the hotel, only Angel Dust and Lucifer. The difference between them was that Angel Dust had an odd scent of gunpowder and roses—something Alastor could easily ignore. But Lucifer? Lucifer was a problem. You would think he was mated already, but no, Lucifer was still unmated, despite being with Lilith for centuries. It was odd, but Alastor wasn't about to ask.
He locked himself inside his room days ago in preparation for his rut. The swampy atmosphere did little to calm the fever under his skin, but at least the thick wood door muffled Lucifer’s scent—mostly. Alastor paced. He’d tried everything: cold baths, distractions, even binding his own wrists in case the instincts grew too strong.
He hated how Lucifer's room was on the opposite side of the hotel, yet he could still catch whiffs of him—like the scent was actively seeking him out. He was on the first day of his rut officially now, and the feverish haze was worse than usual. He didn't usually have ruts when Omegas were around—his instincts never triggered unless they were unmated. That's why Angel Dust never bothered him. The spider was constantly surrounded by pheromones that weren't his own, marking him as taken in a way Alastor's body respected.
He had also told Charlie—briefly, clinically, as if discussing a mild inconvenience—that he was about to have his rut. The way her brows furrowed in concern almost made him laugh. "You're locking yourself away?" she asked, voice pitching higher than usual. "That seems... extreme. Maybe we could-"
"No," Alastor interrupted, teeth gritted just slightly too tight. "Just keep everyone away from my room. Especially your father."
Charlie opened her mouth, then closed it. A flicker of understanding passed over her face, followed by something almost mischievous. "Right. Because he’s…?" She gestured vaguely toward the upper floors where Lucifer’s quarters were.
"Precisely. And if you value structural integrity, you’ll make sure he doesn’t come knocking." Alastor flashed her a grin sharp enough to draw blood, though his fingers were already digging into his palms behind his back. The scent glands at his wrists burned—he hadn’t bitten them shut in decades, but the urge to gnaw his own flesh off just to stop the thrum of pheromones was alarmingly present.
Charlie hesitated, then nodded once. "Okay. And…" She chewed her lip. "Dad—he’s still unmated, you know. Despite everything with Mom." The words came out in a rush, like she'd been holding them back for centuries. "I don’t know if that matters to- to whatever’s happening here, but-"
Of course he knew that obvious fact. What Alastor hadn't known—what twisted his insides into something feral—was that Charlie knew. That she'd watched her parents dance around each other for millennia, never quite sealing what should have been an inevitable bond. The implication settled in his marrow: Lucifer's body had waited. His scent glands remained unmarked, his instincts perpetually coiled tight. No wonder his pheromones were so potent—they'd been bottled up for literal ages, fermenting into something intoxicating.
Alastor woke up again—for the third time in an hour—with his teeth buried in the pillow, cotton stuffing bursting between his teeth like some poor imitation of flesh. He spat it out, disgusted, and rolled onto his back, staring at the cracked ceiling. The air was thick with the musk of his own frustration, the scent cloying even to him. He needed to move. Needed to—no. No, he didn’t. He needed to stay put, locked away like the beast he was refusing to become.
He was trying to sleep through his rut—or at least, sleep through the worst of it. The bedframe groaned under his weight as he shifted again, skin slick with sweat. He'd stripped hours ago, the clothes too constricting, the fabric choking him with every breath. The swampy humidity of his room clung to his bare skin, amplifying the heat simmering under his surface.
He groaned, pressing the heels of his hands into his eyes until stars burst behind his lids. The fever felt worse than any rut he'd endured before. His pulse thundered in his skull, each heartbeat a relentless drumbeat of need, need, need.
The pillow wasn’t enough. Neither were his own hands. Alastor snarled, kicking the ruined bedding aside as he stumbled upright, claws gouging the air like he could tear the need out of his own ribs.
He wanted—no, needed—to bury himself in something warm and willing, to fuck until his hips ached and his knot swelled fat with completion.
The problem was, the only thing he wanted was currently lounging somewhere on the opposite side of the hotel, blissfully unaware of the havoc his scent was wreaking. Alastor dragged a hand down his face. The sting did nothing to quell the fire in his gut. He considered—briefly, deliriously—just breaking down the door and taking what he wanted. Lucifer wouldn’t stand a chance. The king of Hell might be powerful, but biology was biology. Omegas were built to yield, no matter how sharp their teeth were.
Wait... was he also imagining the door creaking open?
No. This wasn’t happening. Charlie had promised—she’d sworn—to keep everyone away. Especially that apple and cinnamon scented Omega who was currently stepping into Alastor’s room.
Lucifer sniffed the air delicately (Alastor was unsure how.. only that he heard it). "Holy, it reeks in here." He stepped further inside, the door clicking shut behind him—not that Alastor registered the sound over the roar of blood in his ears.
Alastor’s bed was hidden by the trees of his room, but Lucifer stepped forward confidently, as if he already knew where to go. He could smell Lucifer now—thick and syrupy, honeyed apples soaked in cinnamon—and it was wrong, wrong because it wasn’t laced with fear, wrong because Lucifer wasn’t running.
"Charlie seemed very insistent I shouldn’t come check on you. Which, naturally, made me curious." Lucifer’s voice dripped with amusement, his boots clicking against the damp wood floor as he stepped deeper into the room. He flicked a fallen vine out of his path with the tip of his cane.
Lucifer paused at the edge of the bed, tilting his head. "Well. Aren’t you a sight," he mused, gaze dragging lazily over Alastor’s bare form. His fingers tightened around the cane, but his voice remained light.
"What." Alastor panted. "Are you doing here?" His voice scraped raw, barely recognizable even to himself.
Lucifer blinked at him, slow and unimpressed, like Alastor was the one being unreasonable. "Checking on you," he said, as if it were obvious. "Charlie was worrying about you. What kind of father would I be if I didn't investigate?"
A shudder ran through Alastor's frame—not from restraint, but from sheer disbelief. Because Lucifer wasn't reacting. But his pheromones were. The scent rolling off the king wasn't just passive sweetness anymore; it was thickening, deepening, syrup spiked with something headier. The scent of an Omega responding—unconsciously, inevitably—to an Alpha's rut.
"Honestly, locking yourself up like—" His breath hitched, just slightly. He cleared his throat, plowing forward, "—like some feral animal is beneath you." Lucifer waved his cane dismissively, but his fingers trembled around the handle. A bead of sweat slid down his temple, though the room wasn't nearly warm enough to justify it. His skin prickled—had the air always been this thick?
Alastor moved before he could think—before his higher brain functions could override the primal scream of his instincts. One moment, Lucifer was standing there, all smug amusement and casual disregard for the danger he’d waltzed into. The next, he was under Alastor, pinned to the bed with a startled gasp.
Lucifer’s scent was amplified. “You stupid, stupid little Omega,” Alastor growled, pressing his nose into the hollow of Lucifer’s throat, inhaling deeply. "Omega’s don't walk into Alpha dens alone." His claws dug into Lucifer’s skin. “Unless they want to be bred.”
Lucifer arched beneath him, not in struggle but something closer to instinctive surrender—his body curving into the press of Alastor’s weight. "Oh?" His voice was breathless. "And what if I do? Maybe I wandered in here hoping you’d put a litter in me." The sarcasm in his tone was thick and exaggerated, the way Lucifer always sounded when he was mocking something.
But Alastor couldn't hear the sarcasm—not through the thick haze of rut clouding his senses. The words put a litter in me rang in his skull like a gong, drowning out all reason, all restraint.
Lucifer's smirk faltered when that didn't bring the reaction he wanted. "Wait-" He squirmed, but couldn't move under the heavy weight on top of him. "You're not actually- ah- hold on!- I was joking," he gasped.
The irony was almost poetic. Centuries of evading bonds, of dodging the inevitable pull of biology, all undone because he’d fucking teased an Alpha in rut.
"You-" Lucifer’s voice cracked. He swallowed, trying again. "You really want to put a pup in me, don’t you?" It wasn’t a question. The evidence was pressed against his thigh, hot and insistent. "Mm- holy fucking shit- I'm soaking wet-"
Lucifer hadn't realized—hadn't noticed the slick between his thighs until he shifted, until the fabric of his pants rubbed against skin already slick with arousal.
The demon's claws traced the seam of Lucifer's trousers, the fabric already damp with slick. "Could rip these off. Should."
The claws tracing his inner thigh weren’t gentle—Alastor’s grip promised ruin, and not the fun kind. His favorite waistcoat was custom made, damn it. “Wait-” His voice cracked, high and breathless as Alastor’s teeth grazed his scent gland. A shiver tore down his spine, but he managed to snap his fingers before Alastor could shred fabric.
The magic left him bare beneath Alastor in an instant. The air hit his damp skin like a shock, but not half as much as the way Alastor's pupils blew wider, black swallowing crimson at the sight of him. Lucifer arched an eyebrow, trying for nonchalance despite the way his thighs trembled. "Fine," he breathed, the word barely audible over the pounding of his own pulse. "Go ahead."
It was permission—not surrender—but Alastor took it as the latter anyway. The air between them thickened further with the scent of Lucifer’s slick. It was sweet, cloying, almost unbearably rich, and Alastor’s nostrils flared as he inhaled deeply. His tongue darted out to wet his lips, the tip dragging slowly over his teeth, like he was savoring the anticipation.
The king’s legs trembled, but his breath came steady, even as the sinner ducked his head down and inhaled, nose pressed against Lucifer’s inner thigh. Alastor’s tongue dragged up the seam of Lucifer’s thigh in one slow, filthy stroke, collecting the slick that had gathered there. The taste was overwhelming—thick honey, tart apples and cinnamon heat—and Alastor groaned low in his throat, pressing his tongue harder against Lucifer’s skin just to chase more of it.
Lucifer's breath hitched as Alastor's teeth grazed his inner thigh. His fingers twisted in the damp sheets, claws tearing through fabric as the Alpha's tongue lapped at the slick dripping down his legs. The sensation was dizzying, overwhelming, wrong in a way that made his stomach clench.
Because that was the problem, wasn't it? The slick, the trembling, the way his body arched into Alastor's touch—none of it felt wrong at all. It felt right, horrifyingly so, and that was what twisted Lucifer's insides into knots tighter than Alastor's rut-driven grip. Centuries of marriage to Lilith, a woman who could control her second-gender better than Lucifer ever could, who never let biology dictate her desires and needs—had it conditioned him to believe this was wrong? Or worse—was he doing this because she'd never let him?
Lucifer's breath stuttered as Alastor's mouth dragged higher, teeth scraping the delicate skin where thigh met hip. Has Lilith ever made you feel like this? The question was poison, syrupy and thick, clinging to the back of his throat. He loved her. He did. But love wasn't the same as this.
The last time he'd felt this—this hunger, this desperate, clawing need—had been two hundred years ago, when Lilith had pressed him into their sheets with her teeth at his throat and her fingers inside him, stretching him open for the press of her cock. She'd knotted him only once, just long enough to put Charlie in him, and then never again.
"Mgh!-" Lucifer's thoughts were interrupted by the sensation of a tongue going inside with little warning, his hips jerking against Alastor's face with a wet sound. The Alpha's nose pressed flush against him, inhaling deeply as he worked Lucifer open with broad strokes of his tongue.
Lucifer’s fingers tangled in Alastor’s hair, tugging hard enough to make the Alpha growl against his skin—a sound that vibrated straight through him, pooling low in his belly. The vibration sent slick dripping down his thighs, and Alastor groaned again, lapping it up greedily.
Alastor pulled back just enough to smirk up at him, his mouth glistening with Lucifer’s slick. “Delicious,” he purred, dragging his tongue over his lips. His claws dug into Lucifer’s hips, pinning him to the bed as he leaned down again, this time bypassing his thighs entirely to press a hot, open-mouthed kiss to Lucifer’s cock.
Lucifer’s breath stuttered as Alastor’s mouth enveloped him, heat and wetness swallowing him whole. The sensation sent another round of slick gushing from him, dripping onto the sheets beneath. Alastor groaned around him, the vibrations making the angel moan, head thrown back as his fingers twisted tighter in crimson hair.
Alastor pulled off with a filthy pop, tongue dragging along the underside one last time before he sat up. "You're letting me put my knot in you?" He said, voice rough.
Lucifer blinked down at him, chest heaving. "I said 'go ahead' didn't I?" He tried his best to sound funny—anything to break the tension—but the words came out breathless, shaky. "Kinda implies you can do whatever. Within reason," he added hastily, as if that would somehow temper the feral hunger in Alastor's eyes.
As much as Alastor would love to egg Lucifer on, his rut-addled brain could only focus on one thing: breeding. His fingers dug into the meat of Lucifer’s thighs, spreading him wider. "Then let's not waste any more time," he said, voice rough with need.
The Alpha positioned himself between the blond man's thighs without another word. The feeling of slick against the tip was dizzying—hot and thick, clinging to him like syrup. Alastor groaned, the sound deep and guttural, as he dragged the head of his cock through the mess, smearing it down his length. Lucifer's scent was everywhere, overwhelming his senses, and for a moment, Alastor just stayed there, rutting shallowly against him, coating himself in that addictive slick.
The groan that Lucifer produced when he pushed in vibrated through both men—a sound so deep and desperate it might have been embarrassing if either had the presence of mind to care. But they were too focused on listening to their biological instincts, which were screaming at them to mate.
There was little resistance—only the tight, wet heat of Lucifer’s body yielding beautifully around him. The mentioned Omega had thought himself prepared, had braced for the stretch, but it seemed it wasn't enough. His body did its best to push and squirm away from the intrusion—not due to discomfort, but due to instinct—only to be held down by claws digging into his thighs.
A gasp tore free, muffled by teeth sinking into the nearest surface—Alastor’s shoulder—as if biting back the sound could somehow salvage dignity. It didn’t. Not when the second thrust dragged a moan from his throat, low and broken, nor when the third had his legs trying to lock around Alastor’s waist, their height difference made it difficult.
Lucifer’s claws raked down Alastor’s back as the Alpha bottomed out again, each thrust seemingly deeper than the last. The stretch was different, and he could tell even after seven years apart—Alastor was... bigger than Lilith. His wife never bragged about her size being above the average Alpha, but Lucifer certainly did—though that wasn't exactly a topic he'd bring up now.
All that mattered was the fact that the thick and lengthy intrusion was currently causing the Omega to see stars and lose all his senses. Especially when his sweet spot was hit with precision—again and again and again—with no mercy nor pause—just pure aggression that had Lucifer choking on his own breath.
"Fuck- fuck-" Lucifer's voice cracked on a sob as Alastor's hips snapped forward, the angle shifting just enough to grind against that spot inside him a second longer.
The mess was unreal. He hadn’t been this wet since—fuck, since never. Lilith had never wrung this out of him, not even during her own rare ruts. Lucifer’s thighs were sticky with it, the sheets beneath him soaked through, and every time Alastor pulled back, the obscene squelch of slick coating his cock made Lucifer’s stomach twist with something between humiliation and dizzying arousal.
It dripped down Alastor’s thighs too, pooling where their bodies met, and when the Alpha ground his hips forward again, the sound was filthy—wet and sloppy, like skin sliding through honey or mud. Lucifer’s fingers scrabbled at the sheets, claws tearing through fabric as another wave of slick gushed out around Alastor’s cock. “Ah- fuck-” Lucifer gasped, his thighs trembling. "You’re- you’re making a mess-"
Alastor’s laugh was breathless. "You are," he corrected, voice thick with pleasure, dragging his tongue over his teeth. "So wet for me. Soaking my mattress with that pretty slick of yours." His hips snapped forward again, punctuating the words with a deep, grinding thrust that had Lucifer's back arching off the bed. The Alpha’s claws tightened around Lucifer’s thighs, pinning him harder against the sheets as if to say stay put—like Lucifer could even think of moving now, when every nerve in his body was alight with the relentless rhythm of Alastor’s rut-driven pace.
Lucifer’s hands flew to his own stomach, pressing down as if he could feel the shape of Alastor inside him through his skin. The thought alone sent another gush of slick between them. "Oh- shit-" His breath hitched, thighs tightening reflexively.
The Alpha’s rhythm stuttered—just once—when Lucifer’s fingers pressed harder against his own abdomen, a silent acknowledgment of the purpose behind this. "Fuck," Alastor hissed, his claws flexing against Lucifer’s thighs. "You feel that?" His hips rolled deeper, grinding in tight circles until Lucifer clawed at his chest from the overstimulation. "Feel how deep I’m in you?" He kept rolling his hips."That’s where I’m gonna put my seed. Where you’re gonna keep it."
The Omega in Lucifer was purring, delighted at the prospect—no, the certainty—of being bred. It didn’t care about pride or logic or the complicated history between their bodies. It didn’t care that Lilith had never made him feel like this, that she’d never chased his pleasure with single-minded devotion, never pressed him into the sheets with the sole purpose of filling him up. It didn’t care that this was Alastor, of all people, rutting into him like an animal.
All it cared about was the way his belly warmed with every thrust, about the growing knot at the base of the length inside him promising to lock them together—promising to keep him full. Lucifer’s omega preened under the attention. Yes, it seemed to sigh, this is what you were made for.
A clawed hand slid between their sweat-slicked bodies, fingers curling around Lucifer’s member with a grip that was punishingly tight. The man made sure to pump him in time with his thrusts—each roll of his hips forcing Lucifer further into his own fist.
Lucifer’s thoughts were fraying at the edges, unraveling under the dual assault of Alastor’s cock grinding deep inside him and the tight fist working his own. His walls clenched even harder around the Alpha’s length, slick managing to gush out with every thrust.
A high, keening sound tore from Lucifer’s throat as his body coiled tight, every muscle straining—then snapping. His climax came suddenly, violently, like lightning splitting the sky, and Alastor felt thick white liquid coat his hand and Lucifer’s stomach as the Omega arched beneath him, hissing through clenched teeth.
Not only that, but the demon could feel a new round of slick coating his cock, making the slide even easier. Alastor groaned around the tightness squeezing him—Lucifer’s body milking him with every pulse of his orgasm—and he knew he wouldn’t last much longer. His knot was already swelling, pressing insistently against Lucifer’s rim.
"Hah... get ready.. mmh-" Alastor's voice was drowned out by the static in his words as his hips stuttered. The knot was swelling rapidly now, and with one final thrust, it popped past the rim, locking them together.
Lucifer gasped sharply, hands flying to his stomach again—not to push away, but to press down against the sudden stretch. His fingers splayed over his abdomen as pulsing warmth filled him, wave after wave spilling deep where Alastor’s knot held them locked together. The sheer volume made his belly swell visibly, rounding beneath his palms like he’d swallowed something far too large.
Lucifer’s breath came in heavy pants as he stared down at the slight curve of his stomach. His throat clicked when he swallowed, voice cracking as he whispered, "Holy shit, you really filled me up. Must have been saving that for a while." The weak attempt at humor barely masked the tremble in his voice.
Alastor’s answering sound was less laugh and more growl, his teeth suddenly sinking into Lucifer’s scent gland on his shoulder. Lucifer’s entire body locked up, hands flying to Alastor’s hair to yank him back before the Alpha could seal what his instincts were screaming at him to complete—a mating bite. But it was too late. The sharp sting of teeth had already drawn blood.
No. No no no. He couldn’t be marked—not like this, not when he wasn’t even sure what this was. Lucifer’s fingers twisted tighter in Alastor’s hair, wrenching his head back with enough force to make the Alpha snarl. Blood—his blood—dripped from Alastor’s teeth, gold against gold, and Lucifer’s pulse hammered in his throat where the bite throbbed.
"Mm. No marks," Lucifer hissed through clenched teeth, shoving Alastor’s face away with more force than necessary. Gold ichor welled at the shallow puncture on his shoulder, a start of a temporary bond already forming. He refused to acknowledge the way his omega whined at the rejection—how it ached to pull away from the claiming teeth of an Alpha in rut.
They were still locked together by Alastor’s knot when both men managed to catch their breath. Lucifer's slick still dripped sluggishly around where they were joined, his thighs sticky with the aftermath.
What... have I done..?