I NEED HELP!!!!

I NEED HELP!!!!

So if you remember Alastors speech on hazbin hotel on how "a smile is a valuable tool and keeps your enemies guessing" well I wrote these two scenarios of my OC Aria with nightmare sans who i ship with her

If you're wondering who My OC is Aria is a demon she is immortal 335 years to be exact and she is kind of on a spectrum of working with nightmare and being in a relationship with him

(go below)

But this isn't about my OC this is about my two scenarios, So I wanted to hear your responses of this.

First scenario:

Nightmare got to meet Aria who he became slightly over obsessed with, actually fell in love. the one time she actually did show a negative emotion he became kind of addicted to it wanting more over time. nightmare tried tricking Aria into being with him over and over until eventually winning her heart... or so he thinks... Eventually Aria does things that make Nightmare feel real emotions for her and finds out the she actually manipulated him to the point that he didn't know.... Which she quote on quote said, "how to predator became used by the prey" which leads to the question 'how did she?'

Which comes to my second scenario:

When Aria and Nightmare first met nightmare notice she smiles a lot....never ever stop smiling, kind of like how Alastor does. the only difference between the two of course is that Aria smile seems different...nightmare being the king of negativity, Can see that her smile isn't necessarily true. yet no matter how many times he tries to make her mad he cannot and she always smiles. If you look into her smile you see that her smile isn't just what you think it is... She was able to fool dream and killer and everyone around her. Her smile...her always acting such a joyful and kind person, when reality that smile was nothing but a manipulative trick.

Which leads you guys to tell me how would he feel for these two scenarios?