Pulling My Heartstrings (Undertale Au Smut)

Nightmare x Reader

I shifted slightly in a nervous state, I was sitting in Nightmares office because I'd been... well... flirting with him in front of the rest of the team . He sat on the chair on the other side of the desk with an odd smirk on his face.

"Y/n" He said, making me freeze as it wasn't a question but the start of a statement "You know what happens when someone does something I don't like or disobeys me."

I looked back down nervously, "Y-yes boss, I do. W-what's my punishment going to-"

"Oh no, your not being punished darling-your getting a reward" He interrupted with a dark chuckle.

I looked back up at him, confused, then his hands were on the sides of my face and his lips were on mine.

He pulled away for a second and muttered against my lips,

" Just remember your allll mine and we won't have any problems~"

And then he kissed me again, more heated than the first, his hands trailing to my hips and lifting me up to straddle him on the desk. I let out a soft, rather embarrassed moan as he bit on my neck and licked the mark.

I gasped slightly as I felt an intrusion under my clothes, my eyes fluttering at the feeling. His hand was in my pants and panties and two fingers were slowly pumping into me. His thumb rubbed slow circles around my clit and my eyes rolled back, moaning, I could feel the familiar heat pooling in my stomach.

The hand not fingering me was tangled in my hair and roughly tugged, the pain mixing with the pleasure caused a loud moan to rip from my throat.

My head was thrown back and he was sucking on my neck and whispering sweet nothings in my ear.

" B-boss~!" I moaned and he grinned pulling his hand away, pulling my pants down swiftly.

"Shhh darling~ we don't want the others to hear now do we?~" he purred and I bit my lip trying to stay quiet as he pulled my legs up to wrap around his waist.

I nodded quickly, wanting nothing more than him to be in me.

"Good girl~" he praised, his voice thick with lust and desire. He was slowly teasing my entrance with the tip of his cock and I was writhing.

"B-boss~ P-please~" I whimpered and he smirked.

"You got it sweetheart~"

He slammed into me and I bit my hand trying to keep quiet, the room was filled with the sounds of my muffled moans and his grunts. He was hitting that spot every time and it was so good, I could feel myself coming undone.

He grabbed my hips and started slamming into me faster, the lewd noises were driving us both crazy.

"Ah~! B-boss~" I moaned and he pulled me closer, his hand wrapping around my throat.

"Quiet darling~" he purred, his hand tightening on my throat, choking me.

I let out a choked moan, the pleasure and the pain was amazing, the lack of air making the experience even better.

My legs tightened around him, my body quivering and spasming as I was coming closer to my end.

His thrusts became faster, harder and more erratic as he was reaching his end as well.

He let go of my throat and I sucked in air, trying to make up for the lack of air.

He growled slightly as he hit my g-spot once again, the hand on my hip gripped tightly as his thrusts became more rough and I came undone, his name falling from my lips in a loud scream as I reached my peak.

He followed right after me, filling me up and letting out a loud, animalistic groan.

We both sat there panting for a minute, him still inside me.

After a while I was lifted up and teleported to the bed in his room and he pulled me close, nuzzling his face in the crook of my neck.

"Love you, y/n" he muttered sleepily , actually admitting it for the first time and I smiled, blushing lightly.

"I love you too, Nightmare" I whispered.

"Nightmare?" He repeated and I hummed in response.

"That's the first time you called me by my name" He muttered, pulling me closer, "Say it again"

I giggled lightly, "Nightmare"

He let out a content sigh and held me close, his tentacles curling around me.

I slowly drifted off, a smile on my face.

"You're mine" he muttered and we both fell asleep.

- extra bit -

I woke up in the morning with a yawn, finding myself in nightmares bed with a deep blush on my face.

"Morning sleepyhead~"

I jumped at the sudden voice and looked around, my eyes landing on him standing beside the bed.

"B-boss??" I exclaimed, covering my bare chest.

"Yes, and you better be glad the others aren't here or they would have heard us last night~"

I blushed more and looked down, remembering exactly what happened.

He chuckled and sat on the bed, crawling up to me.

"I don't regret a thing" He purred in my ear, his voice sending shivers down my spine.

He was leaning over me and his hands trailed down to my hips, a devious grin on his face.

I smiled lightly, his grin making me smile too,

"Me either"

And his lips crashed into mine, pulling me into a heated kiss, his tongue forcing it's way into my mouth.

I let out a small, soft moan and he grinned, pulling away and leaving a trail of kisses and bites down my neck and chest,

"I love you and your reactions to me, your all mine and it's utterly adorable ~"

I smiled softly, my heart fluttering in my chest.