W. D. Gaster x Reader

Be Gentler On Me

(Smut, dark, Underfell)

Get a guy who can do both, a geek in the streets and a freak in the sheets. Well, I did. Dr. Wingdings Gaster. A respected scientist who is now my boyfriend, of sorts. I was at first an experiment, until he grew fond of me. Now I'm more like a prisoner and sort of a friend, but Alphys teases me on our "relationship" so I assume I must be his girlfriend.

The comes the freak in the sheets. He's a masochist and a sadist. Extremely. But more of a masochist though. An example would be, one time I got mad and I punched him in the ribs, nearly breaking one. He blushed, moaned, and he asked me to do it again. But when he's topping, he's a sadist. Though he's much lighter on me, mostly because he doesn't know how much my body can take since I'm not monster. The worst he's ever done is cut me. And in all honesty, I don't really like it. I don't think it's weird or that it's wrong to like those things, I'm just not into it. Of course I don't tell him that, I act like I love it, faking every orgasm. But he doesn't know that.

Though, one person does. Alphys. She sort of understands. She loves it rough and wouldn't mind an injury, as long as it isn't on purpose. "Well, you know how he is. He's extreme. But I'm sure if you just told him, he'd respect that." I raised an eyebrow as her advice. "He would respect that?" "You seem to be the only thing besides his work that he respects at all." She pointed out and I bit my lip. "If you say so." I said, hanging up the phone. I was at the Lab at the moment, the second floor of it was our home, and the basement was his freaky experiment dungeon thing that I don't ever enter. Gaster always stops working for the day around dinnertime, I would tell him then.

Until then, I made us some dinner. Spaghetti. It was one of the few things I could properly consume without it dissolving into energy. It isn't that bad though. I watched Gaster come in, some blood on his coat. He either didn't care or notice because he hung it up anyways. He then came over to me, kissing my forehead and letting out a dark and deep chuckle. The kind that he knew makes me squirm, that I didn't fake. I blushed and he smirked down at me. "Oh, you made dinner? How sweet." He said as we sat down to eat. When I finished I awkwardly sat there a moment, I wasn't sure how to start the conversation. He noticed my unusual behavior, "(Y/N)? What's wrong?" He asked as he finished. He then crossed his arms at my silence. "Tell me. I can probably fix it, whatever it is." He said and I bit my lip. "It's complicated."

I suppose he didn't like the sound of that. He went over to me and he picked me up from my seat, carrying me into the living room and sitting me down with him. "What is this problem that vexes you?" I bit my lip. "I don't uh. I don't enjoy our. Our sex." He was silent. "I. I'm sorry." I felt him pull away some, leaning back against the couch. "Well. You should of told me. Nevertheless, what about it do you not like. Is. Is it because I'm not human?" He questioned and I shook my head. "Oddly enough, I don't care about that. It's just. You're really rough. I haven't enjoyed it, for a long time. Or. Ever. Honestly." He sighed softly, "You've been faking?" I nodded. "I don't even know what a girl's moan is suppose to sound like. I just, made up noises." I looked back at him. He was frowning.

"So. I shouldn't hurt you then?"

That sort of surprised me. I expected anger, rage, it being my fault. Instead, he stays calm. He was taking it surprisingly well. "Well. Yea. That would help a lot." He nodded at this. "What would you like me to do to you instead then?" I furrowed my eyebrows, he smirked some. "You heard me. What do you want me to do to your body?" "U-Uh." He pulled me closer. "How about we find out together?" He tempted. He then picked me up again and carried me into our bedroom. He laid me down and he licked his lips as he crawled over me. "W-What are you g-gonna do t-to me?" He smirked, "I'm gonna make you feel good." He said confidently, but I shouldn't of expected complete sweetness, after all, it's a work in progress. He ended up tying me to the bedposts, I really should of expected that.