W. D. Gaster x Reader

I'm Not A Boy: For Me

(Smut. It sucks cause I wrote it late at night and on very little sleep.)

Tonight was the night I take what I want.

It's been two weeks since Gaster's teasing, two weeks of hell. Him constantly grabbing my ass, whispering in my ear, hitting on me, I was at my limit. I was ready to explode.

Tonight, after Gaster fall asleep, I'm gonna tie him up and take what's mine. I'm gonna use his body to please me until I'm done with him. And I'm not gonna stop until I'm satisfied.

It was midnight and I was ready to go into action. I had to grab four scarves that I could use to tie him up. I smirked as I snuck in his room. I carefully made it in there and approached the bed. I looked down at his sleeping form. He was on his back, slightly curled up to the right, and looking so adorable.

I slowly tied his hands to the headboard, I then tied his ankles to the footboard, I smirked as I uncovered him, revealing his bare top and some boxers. I licked my lips and I sat back down on his waist, gently, I rocked my hips some and I bit my lip as I felt something grow between his legs. I smirked as he slowly woke up. His eyes widened when he saw me on top of him, rocking back and forth, I could tell he was already regretting how he teased me, good.

"Hey sleepyhead." I greeted as he struggled to free his limbs I chuckled, "Don't bother, I tied you up pretty good." I said as I played with the waistband on his boxers. "I-It isn't fair if I'm naked and you aren't." He said but I just shrugged, "This isn't about being fair, this is about taking what I want from you." I said before pulling his boxers down to his ankles. I squirmed at the sight of the glowing purple magic between his legs. I bit my lip hard as I stared down at it.

I began pulling my clothes off, frantically trying to free myself from the fabric. I then hovered my entrance over his length before slowly sitting down. I moaned out as I was finally filled. I bit my lip and I began rocking my hips, Gaster was moaning beneath me. I smirked as I lazily grinded back and forth, causing him to continuously rub against my g-spot. I gripped his bottom ribs and he gasped and arched his back. I curiously began to rub and stroke his ribs, he moaned and squirmed in pleasure.

I smirked and moaned softly as I heard Gaster was moaning and letting out soft whimpers. "I-I didn't expect you to be so gentle." He said and I smirked, "If I wanted to fuck you hard, I would, easy. But bouncing takes too much energy, and this is about my pleasure, not yours. So I'm gonna do whatever I have to, to make sure I enjoy this. I don't even care if you cum or not, I'm just here to take what I want." I said as I continued to move my hips, moaning out in pleasure, I gasped when I felt hands on my breasts, I forgot he can conjure up hands.

I trembled and arched my back when they played with my nipples. I panted softly and moved my hips a bit faster. I began to moan out and shake as I was giving myself a deep massaging on my g-spot with his cock.

I moaned out and rocked my hips faster, taking what I finally needed. I blushed as I felt something build up in me. It was like I was becoming hypersensitive to everything, it all began to feel even better. I gripped a rib in each hand as I frantically moved my hips and moaned out for him. It felt so good. I felt myself explode.

It was like every muscle in my body tensed and then relaxed all at once, I let out a cry as pleasure racked through my body, hitting me in waves like the ocean. I panted softly and blushed at the feeling. I then looked down at Gaster with a satisfied smirk. He was still whimpering and panting, he wasn't even close.

I chuckled some, "Hm. Lucky for you, I'm not done playing with my toy. I hope you don't have any plans tomorrow." I was getting my second wind, I felt great and energized, I smirked and began to bounce and ride. I moaned out as I solely did it for my pleasure, though I did love the loud moans beneath me. Gaster was crying out, he was desperate, I could tell. I smirked and rolled my hips, grinding more than bouncing. I moaned out and I arched my back as I felt myself getting close faster than before.

Last time I hardly lasted ten minutes, but this time I think I might get cut short at five.

I moaned out and moved more frantically, trying to get faster and deeper. I wanted him, badly. I wanted to cum. I was gonna have what I wanted no matter what.

I moaned and moved faster as I felt his pelvic bone rubbing my clit. I moved faster to get some more friction, it felt so nice. I moaned and trembled as the pleasure began to take over. I rolled my eyes back and grinded my hips faster and faster, I let all my moans and cried just fall out, I needed this.

I cried out as I felt my hips moving faster and faster, it felt so nice. I felt my body tremble and my legs shake as I got closer. I noticed Gaster was moaning like crazy, he seemed hardly in control of himself. I smirked at this and I watched him shake and moan out under me. He was calling my name, begging for more, craving me as much as I craved him.

I froze and nearly collapsed on top of Gaster as I came, I tremble and whimpered as I laid on him, his magic hands untied his binds. I then felt two arms wrap around me as he finished releasing into me. I smirked up at him and he was blushing some, "I can't believe you just came in here while I was asleep and decided to tie me up and have sex with me." "I can't believe you didn't see it coming." I responded and he rolled his eyes. "Well, I'm glad you did it." He confessed and I smirked, "I know." I held on to him, "But take this as a lesson. Next time you wanna tease, you're better off just giving me what I want. Cause if you don't, I'll just take it." I winked. Gaster licked his lips, "I wouldn't mind if you took it more often."