summary: living in helheim’s most secluded laboratory with beelzebub usually means strict silence and an overwhelming, heavy atmosphere. but when your brain fires off an uninhibited impulse, all decorum and basic safety protocols fly right out the window.
word count: 1,309
warning(s): fluff, ooc, flustered beelzebub, reader letting invasive/intrusive thoughts win, light nibbling/biting, squeezing muscles, playful shenanigans, domestic helheim life, lowk made reader a bit annoying into this (mb gang), lmk if I missed anything!
a/n: I'm a firm believer that once beelzebub lets his guard down with someone (and once he lifts Satan's curse) he's the gentlest lover ever<3 this could take place in an au where Satan and beel coexist somehow??? idk man, I tried to write this as fluffy as I can but I can't really do that in the canon universe. if I did, it would turn out rather angsty due to his avoidant personality
>og request<
The quiet within Beelzebub’s sanctuary was usually absolute.
Deep beneath the gloomy, quiet expanse of Helheim, his personal laboratory operated under a strict, unspoken code: do not touch the vials, do not make sudden loud noises, and under no circumstances disrupt the Lord of the Flies while he was writing.
Because it was an unusually humid afternoon in the realm, Beelzebub had actually done something rare. He had shed his signature oversized, heavy black coat, leaving it draped over the back of a high-backed velvet chair. He was sitting at his grand obsidian desk in just a sleeveless dark top and fitted trousers, pale skin exposed to the dim candlelight as his pen scratched rhythmically against ancient parchment.
He felt comfortable. Unprotected. Totally relaxed.
And that was his first mistake.
You didn't need to knock for permission to enter—somewhere along the way of your relationship, he had let his guard down enough to let you into his most private room. Even without express permission, after all Beelzebub didn't need to say his thoughts out loud in order for you to understand him.
You stepped into the laboratory carrying a tray of iced tea, initially intending to be on your absolute best behavior. But the moment your eyes locked onto him—his lean, surprisingly defined shoulders, the smooth expanse of his pale skin, and the messy mop of dark hair—your brain instantly shut down all normal, rational human processing.
Intrusive thought loaded: 100%.
You didn't pause to think. You didn't even drop the tray loudly. Like a spy, you carefully, methodically set the tea down on a nearby side table, took three quiet, calculated steps backward to build up momentum, and then took a running leap.
"Beel!"
Beelzebub turned his head just in time to see a blur heading straight for him. Before his centuries-old combat reflexes could even process a defensive ward, you dived face-first directly into the center of his chest.
THUMP
The force of the collision sent his heavy mahogany chair rolling backward a good foot on the stone floor. A sharp, involuntary "Oof!" escaped his lips as your forehead slammed squarely into his pecs.
"(Name)?" Beelzebub gasped, his pale face instantly flushing a bright, furious crimson. His arms flew up in pure panic, hands hovering awkwardly in mid-air near your shoulders like he was afraid he might break you—or that you were about to detonate. "What are you doing?"
Instead of offering an explanation, you buried your face deeper into the soft dark fabric of his top, inhaling the subtle scent of old paper and ink, before reaching out and wrapping your fingers tightly around his biceps, squeezing with absolute dedication.
"Density test," you muffled into his chest, giving his left arm a vigorous squish. "Yup. How are you built like a brick wall when all you do is sit here and read all day? It’s unfair. Where are the muscles coming from, Beel?"
Beelzebub let out a shaky, long-suffering sigh, his shoulders slowly dropping as he realized he wasn't under attack by a rogue monster—just under the mercy of your complete lack of an impulse control filter. "I am a god," he murmured, his voice gravelly and deeply flustered. "My biology does not work like yours... and you are completely unpredictable."
"You love it, don't you?" you declared, finally lifting your head off his chest.
Your faces were only a few inches apart. From this vantage point, sitting directly in his lap, you had a crystal-clear view of his features—specifically, his pointed, elf-like ears poking out through his messy black hair.
Your brain fired off another immediate ping.
Touch them.
No, wait... bite them.
"Y/N," Beelzebub warned, a rather futile effort, his dark eyes narrowing slightly as he caught the sudden, wild glint in your eyes. "Whatever thought just entered your head, execute an immediate shutdown—"
Too late. You reached out, running your thumb over the soft, cool skin of his pointed ear. It was delicate, smooth, and surprisingly warm to the touch. Before he could lean away, you leaned forward and gently took the pointed tip of his ear between your teeth, giving it a playful, soft nibble.
Beelzebub went completely, utterly rigid.
A tiny, involuntary gasp squeaked out of his throat—a high-pitched sound he would strictly deny ever making under threat of eternal execution. A massive wave of dark heat rushed straight to the tips of his ears, turning them a bright, undeniable red.
"(Name)!" he squeaked, scrambling backward in his seat and clapping a hand firmly over his bitten ear. He stared at you with wide, utterly bewildered eyes. "You can't just bite people! That is not a normal interaction!"
"It's a sign of high affection in my culture!" you lied smoothly, crossing your arms while remaining firmly planted in his lap. "It means I think you're cute."
He groaned, covering his entire glowing face with both hands and sinking back into the velvet cushion. "You are going to give me a heart attack long before any curse ever gets the chance..." he muttered through his pale fingers, though the distinct, soft twitch at the corner of his lips betrayed his attempt to look angry.
While he was covering his face in shame, your eyes wandered toward the corner of his grand desk.
Resting peacefully against the wood was Apomyius—his legendary skull staff. The divine weapon capable of unleashing destructive, high-frequency vibrations capable of obliterating entire armies.
Yoink
"Do not," Beelzebub said instantly, dropping his hands from his face the second he heard your footsteps shift. "Y/N. Step away from the staff."
"Look at me!" you declared proudly, snatching the heavy staff by its handle and holding it up like a conqueror presenting a trophy. "I am the Lord of the Flies now! Tremble before my vibrating stick of doom!"
Beelzebub looked like he was about to faint on the spot. He stood up slowly, raising his pale hands in a frantic, placating gesture like he was dealing with an unpredictable wild animal. "Please. I am begging you. Set it down gently. It channels vibrational energy based on intent and momentum; if you hit the wrong crest on the skull, you will literally vaporize the east wing of the laboratory."
"Can I try once?"
"No!" Beelzebub practically yelled, his composure completely shattering. "Put it back!"
You looked down at the ominous skull staff, then at Beelzebub, whose dark eyes were wide with genuine, sheer panic.
"Fineee," you pouted, carefully leaning the legendary weapon back against the edge of the desk. "You're no fun."
Before he could even exhale the massive sigh of relief building in his chest, you charged back over, diving straight into his arms. You wrapped your legs around his waist and your arms tightly around his neck, hanging off him like a human backpack and burying your face into the crook of his neck with a playful growl.
Beelzebub stumbled back half a step, catching your weight purely out of reflex.
He stood there for a moment in the center of the quiet lab, holding you up, his pale face still flushed. Slowly, a long, soft sigh escaped his lips. His arms slid around your back, pulling you flush against his chest, holding you close as a quiet giggle escaped your throat.
He rested his forehead against yours, looking down into your eyes with a warmth he only ever reserved for you.
"You really just let every single random thought take the wheel, don't you?" he whispered softly, his thumb gently stroking your waist.
"Every single time," you grinned, pressing a soft, warm kiss to his cheek. "Keeps you on your toes."
Beelzebub closed his eyes, resting his chin on top of your head, a faint, rare smile finally breaking across his face.
"I suppose... it does."
a/n #2: chat is it obvious that I REALLY don't know how to write for beel
Being his apprentice was supposed to be simple. However you fell for his kindness and he fell for you too.
It started small. A peck on his sharp cheekbone while he was hunched over a summoning circle. He didn't say anything but the tips of his ears turned red.
You traveled everywhere together. Silent libraries in the Alps to desert markets where he’d buy all kind of sweets just to watch you smile. You would laugh with him until your ribs ached.
But there was always a wall.
He never stayed the whole night. Each time after making love with him. You'd drift off tangled in his robes, your face pressed to his chest where his heartbeat almost sounded human. And every time, you'd wake up cold and alone.
The first few times you let it slide. Then a dozen. Then too many to count.
"You have to stop leaving"
He didn't argue. He just kissed you pushing his tongue inside your mouth one hand grabbing your waist that other hand grabbing your hair leaving you breathless and just like that you forgot why you were angry.
One night, you fought sleep, you willed yourself awake. And when he slipped out of bed , when he pulled his coat over those broad shoulders and looked back at you with something grieving in his eyes.
"Don't."
He froze.
"Stay or tell me why you won't."
Beelzebub turned.
"You and I can never be together, if you stay with me you will become the enemy of the world, it's dangerous to be with me."
“I don’t care.”
“You should.”
“To me, you are my only world.”
That finally makes his expression crack.
“You are being foolish.”
The argument after that is terrible. You accuse him of deciding your future for you. He tells you that you do not understand the consequences of loving someone like him.
Until finally the room falls silent. He steps forward, cupped your face and pressed a kiss to your forehead.
"I'm sorry, I love you."
You never remember him again. Not his face. Not his voice. Almost as if he never existed and yet sometimes you wake up crying for reasons you cannot explain.
And every year, on Halloween night, you return home to find the same thing waiting on your desk.
A single red rose.
You never know why seeing it makes you want to cry.
