Demonslayer x Reader Oneshots

Muzan x Reader

My leg shook vigorously in sync with my wild heartbeat.  Small bites graced the insides of my mouth, a metallic taste tainting my tongue.  Fiddling my thumbs I sat as patient as I could.  It's been a decent chunk of time since I've been called for.  Anyone in my position would be anxious.  Muzan wasn't a man you wanted to disappoint and I was fearful that I somehow had.  I wasn't sure what I had done though.  Was it when I let that small child go?  Was it the fact that I wasn't killing as much anymore?  It could've been anything. 
    
I haven't seen him in about a month due to being sent away to monitor a distant area.  I would never admit it out loud but I missed him.  I wasn't aware how attached I was till I had to live without him. 
    
A new wave of anxiety crossed my mind.  Had I let him down?  Did he miss me?  Has he found a new replacement?  My thoughts ran wild with possibilities and scenarios.  I mean we were only separated for a month.  How much could've happened?  It seemed unrealistic that someone had wormed their way into his barricaded heart in such a short amount of time.  I doubted that someone had taken my place by his side.  I frowned nonetheless even imagining such an atrocity.  The opening of a door shook me from my daze as a demon appeared to address me. 
    
"Master Kibutsuji will now see you," they called timidly.  I rose from my seat, smoothing out my outfit, hoping I looked decent after my trip.  I ran a hand through my hair and inhaled deeply.  Following the demon we stopped before a large door.  I sensed him just on the other side. 
    
The demon pushed open the door allowing me to enter.  Taking tentative steps I inched into the vast room.  I was vaguely aware of the demon quickly bowing and retreating, shutting the door and locking us in with a loud thud. 
    
There he was.  He stood by a window looking out at the moonlit night.  His tall lean body faced away from me, hiding his features from my eyes.  Bowing deeply, I didn't dare mutter a word. 
    
I stayed like that till I felt a hand gently touch my shoulder.  I flinched at his quiet speed, looking up into his blood red eyes.  My breathing hitched at his intense stare.  I rose slowly, his hand not leaving my shoulder.  He wore his usual black suit with a white tie, patterned spirals along the front folds with white pants.  His matching hat was sitting on one of the tables giving me a full view of his dark locks.  His expression was patient as if expecting a response to his touch.  I didn't mumble a syllable, holding my breath in anticipation.  A small amused smile graced his lips making my mind race. 
    
"Welcome back my dear," he smoothly spoke.  My breath sighed out through my lips; just hearing his voice was enough to soothe my worries.  He chuckled darkly.  "Oh my, were you anxious again?"  I blushed, turning my face away slightly.  His hand caught my chin, forcing my head to turn back to him.  "Tell me," he demanded.  I struggled, trying to put together an answer that didn't reveal too much. 
    
"I didn't want to be replaced," I whispered quietly.  Saying it out loud brought new emotions bubbling up to the surface.  Pushing down, I suppressed the million other things I wanted to say.  Staring into his eyes I saw his expression soften.  His hold on my chin slid to cup the side of my face, cradling me softly.  I leaned in slightly, enjoying his touch. 
     
"Oh my dear, I could never replace you," he whispered soothingly.  I practically melted right then and there, my legs trembling slightly.  He chuckled lowly causing shivers to spark down my spine. 
    
"It's quite easy to soothe you isn't it?"  His head tilted to stare at me more deeply as if looking for the answer somewhere in my mind.  My gaze dropped to the floor in embarrassment, my next words barely above a whisper. 
    
"I missed you...".  Before I could register what had happened, I found myself laying back on the couch that had been across the room mere seconds ago.  Muzan was quick and seemed to have grabbed me to throw me on here.  A blush erupted across my face as I looked up at the demon hovering right above me, a knowing smirk pulling at his mouth.  He leaned down, his breath tickling my ear as he spoke. 
    
"I'm never allowing you to leave my side again," he hissed.  A stinging sensation cut through where my jawline met my neck, a warm liquid flowing down my skin to drip onto the couch beneath me.  My eyes widened in shock and disbelief, suddenly aware that Muzan had bitten into my flesh. 
    
His cold lips grazed the spot as I fought back tears, the pain immense and my mind confused.  He chuckled yet again as he pressed a meaningful kiss against the bite before leaving a trail of blood and affection along my jaw.  My arms shot out to wind around his neck as he pressed his lips onto mine. 
    
I gasped at the rough exchange but that only urged him onward as he pushed harder against me.  A metallic taste invaded my mouth and I cringed at the flavor of my own blood.  Of course that didn't stop me from pushing back just as hungrily.  He growled lowly before pulling back, looking like he was ready to lunge at me again.  His red eyes glowed and his mouth dripped red. 
    
I guided my hand to my neck where I quickly felt the wound.  It was already trying to heal but the delicate bruising hadn't faded along with the blood.  Muzan watched me intently as I stared at the crimson shade on my fingers.  I looked back at him as he moved forward yet again, our lips colliding roughly.  I panted for breath but he refused to pull away.  His teeth bit into my lip harshly causing me to cry out.  The sound must've caught him off guard as he quickly pulled away, looking at me with confusion. 
    
I huffed out, kinda tired of the painful play he always loved to do.  It's been so long since we've seen each other I wanted to be cared for affectionately, not eaten alive.  My hands grabbed his face softly, pulling him forward slowly to get the message across. 
    
"Please Muzan, be more gentle," I whispered quietly.  He stared back, his head slightly tilted in consideration before gently cupping my face and placing a sweet kiss.  I hummed in approval as his actions changed to match my request.  His hands were more gentle, his touch softer. 
    
A strange wave of exhaustion seemed to come over me but I ignored it.  Muzan placed small kisses along the side of my face and up to my forehead before pulling away and standing up.  I tilted my head but quickly understood as he grabbed a blanket and draped it over my body.  My actions had been slowing down and he must've noticed as he placed another kiss on my forehead. 
    
"You seem tired.  You should rest my dear and we'll continue this later on if you wish," he spoke gently.  I yawned in response and gave him a grateful smile before turning on my side and allowing my eyes to close. 
    
The wound on my neck had already healed but it was still surprising that he went all the way to bite me.  He must've been stressed while I was gone.  My body calmed and soon enough I had drifted off into dreams of sweet interactions and pleasant passions.