Nightmare Sans x reader

                                    

                                          
(Image above isn't mine)
Don't ask me why, but I had the idea for this oneshot while I was brushing my teeth😅
Enjoy!
Background Knowledge
You live in Nightmare's castle along with all the other bad sanses. For some odd reason, after Nightmare kidnapped you, he decided to abandon his original plan and keep you at the castle. The bad sanses weren't happy with this at first, but they grew to like you.
Your POV
How did I get myself into this? I'm currently standing in the between Dust and Horror who are having the glare-down of the century. I don't even know what they're fighting about. Granted, they fight all of the time. This fight however has a different vibe to it. I glance at both of them wearily, waiting to see who was going to make the first move. It was Dust.
"I can't believe you're so blind to it! Did that hole in your skull do more than just physical damage?!"
Oof! Critical hit!
I saw Horror twitch.
"I'm not the one with issues here. You're clearly the one who needs to get a skull check. Did that kid drive you so insane that you're hallucinating!?"
Oh man. This must be more serious than I thought it was. I try and sneak out from in between them, but Dust grabs my arm. I gulp and turn to look at him. He's still glaring at Horror. 
"Fine. If you don't believe me, then I'll prove it to you."
Horror rolls his eyelights. "You can't prove something that doesn't exist."
Dust insanely smiles before looking back towards me. In one swift motion, Dust brings me into his arms, bridle style. He's still smiling down at me. I shrink back slightly, but there isn't much I can because of his tight grip.
Dust turns around and starts walking off. "Come on, Horror. I want to see the look on your face when I prove you wrong." I hear Horror scoff behind us, but he follows anyway. I'm so confused. 
I look up at Dust. "Hey. Do you think you can put me down? I really don't want to be stuck in between your fight with Horror." 
"No. In order to end this fight, I need you. So you're not going anywhere." I sigh, disappointed. It was worth a shot. They walk in silence and it's beginning to feel uncomfortable. I look to see where we are going and see the door to Nightmare's throne room. Oh no no no no no. My eyes widen and I try to think about how to get out of this.
Whenever Nightmare gets dragged into fights, someone ends up gravely injured. And I did NOT want to be that someone. As we get closer to the door, I start squirming to get out of Dust's hold. But he wasn't having any of it. He just grips me tighter, making me wince. I stop and give in. Welp. It was a nice life. 
Dust opens the doors wide and strides in with purpose. Nightmare is sitting on his throne with a bored expression on his face. He had his elbow propped up on the armrest and his skull was resting in his hand. However, he sits up when Dust walks in. He sighs and closes his eyes(?).
"What do you want Dust?"
He's tone was as cold as ever. Dust, however, doesn't lose his confidence. He looks down at me and whispers. "Just know, everything I'm about to say is a lie." Alright. Now I am thoroughly confused. Dust clears his non-existent throat and speaks. "I came to tell you something boss." 
Nightmare lazily opens one eye socket and looks down at Dust. "What do you wa- why are you holding y/n?" Nightmare, who seems to have just noticed my presence, leans forward in his seat with wide eye sockets. "That's what I came to tell you about." Nightmare narrows his eye sockets at Dust. "What about her?" Yeah. What about me?