(A/n : Hello! So supposedly, this is the option A which is Undertale but, I haven't really done anything that relates to this x reader huh? Well, here is the bonus chap where there's finally some fluff or some fun time with nootmare and no angst and shizz. Let's take a break on what happened in the last chap and enjoy this chap uwu
Btw, this chap hasn't been edited much okay so yea.

And also, Do not play the song yet!)

Y/n = Your name
N/n = Nickname
_______________________________________________________________

(Nightmare's pov)

"Hmm...Arlight then. Let's go to UnderTale." She says. I smiled and nodded.

"Alright then." I grabbed her hand and teleported us into Undertale. The first and original Au. The Monsters in here are outside the barrier and are at peace with humans.

"So, where do you wanna go?"

"Let's go to grillby's restaurant so we can eat first." She says as she pulled me towards the small restaurant of grillby's. We sat on one of the booths. We ordered and started chatting.

"So y/n, where do you and error go mostly?" I asked.

"Well, yesterday we hangout at Outertale again. Last time we also ate at grillby's in underfell. It's fun hanging out with him." She says happily. I can feel my jealousy rising up. I forced a smile.

"Oh really? Well, that is fun." I said slightly gritting my teeth. I heard her giggle as she looked at me.

"Nightmare, Are you jealous?" She says smiling at me. I slightly blush from embarrassment and turned away.

"N-no.." She laughed.

"I think you are nighty." She says. I turned to look at her and noticed her mistake which made her blushed.

"I-I meant nightmare. S-sorry for saying that." She stutters as she looks down from embarrassment. I chuckled. She is so cute.

"No it's alright y/n. There's no need to be sorry for it." I said smiling at her. She look up and smiled back shyly.

"I-if you say so nighty." She says.

(Y/n's pov)

"No it's alright y/n. There's no need to be sorry for it." Nightmare said while he was smiling at me. I look up and returned his smile shyly.

"I-if you say so nighty." I said.

°~•~° Le Flashback °~•~°

"Yyy/nnn!! I'm bored! Let's play." The purple eyed(?) skeleton said.

"Well, what do you want to play?" The little girl asked standing up from her criss-cross position.

"Anything you want n/n!" He quickly says not noticing the name he gave to her. Y/n looked at him confuse.

"N/n? Really nightmare." She says smiling at his friend. Nightmare noticed his mistake and blushed in a purple hue.

"I-I didn't mean to y-y/n. It w-was a slip." He says, trying to defend himself while his blush started growing from embarrassment. Y/n only laughed.

"It's alright Nightmare. The nickname is cute anyway." She says slightly blushing.

"R-really?" She nodded and smiled at him.

"Yeah! And if you're gonna call me N/n then I'll call you Nighty or crescent."

"W-why crescent?"

"It's because of your crown silly!" She says while she pointed the crown sitting onto his skull.

"O-oh.." he says, a small blush forms from the cute nickname. "W-well, nighty sounded nice.." he says quietly to himself. Not knowing his friend heard it making her giggle.

"Well, I'm glad you liked my nicknames for you." She says. "And from now on, I'll call you nighty or crescent! And you call me n/n as you like." She added as she looked at his friend nightmare.

"Alright then n/n."

°~•~° End of Flashback °~•~°

I blinked a few times seeing nightmare looking at me.

"Uhh..you alright y/n?" He asked, his voice had a slight worry in it. I nodded.

"Y-yeah. I just remembered something." I said slightly smiling from the memory.

"Huh, I never knew you were shy and that happy before.." I muttered.

"Did you remembered a memory?" I look up and nodded.

"Yeah I did. I never thought you'd be so cute when you had a purple blush, Crescent." I said. He blushed in a light blue color and looked away.

"W-well, yea when I wasn't corrupted." He says.

(Nightmare's pov)

"Did you remembered a memory?" I asked hearing her mutter. She looked up and nodded.

"Yeah I did. I never thought you'd be so cute when you had a purple blush Crescent." She said. I blushed from her compliment and looked away not letting her see my blush. I tried to remove my blush but, it never left.

"W-well, yea when I wasn't corrupted." I said. C-crescent? That's oddly familiar.. (A/n : Skip this flashback if u want cuz it's just the same flashback from the reader.)

>>°•◇•°● Le Flashback ●°•◇•°<<

"And if you're gonna call me N/n then I'll call you Nighty or crescent."

"W-why crescent?"

"It's because of your crown silly!" She says while she pointed at the crown sitting onto nightmare's skull.

"O-oh.." he says as he slightly blushing. "W-well, nighty sounded nice.." he says quietly to himself not knowing his friend heard it making her giggle.

"Well, I'm glad you liked my nicknames for you." She says. "And from now on, I'll call you nighty or crescent! And you call me n/n as you like." She added as she looked at nightmare.

"Alright then n/n."

>>°•◇•°● End of Flashback ●°•◇•°<<

I had a nickname for her before? Huh, that's a cute nickname I gave her..

"Uhh...Nighty? You zoned out." I was startled by y/n's voice but soon relaxed. I turned to look at her.

"Oh it's nothing n/n. I just remembered some of my past." She looked at me surprised.

"You remembered the nickname you gave me." She says smiling at me.

"It's all thanks to you n/n." I said as she giggled.

"I guess so crescent." She says. Our order soon came. Y/n thanked grillby and started eating.

~~Le smol Tem Skip!~~

After were done eating, we started walking around the city while we hold hands. She started swinging our hands as she hummed a tune that is unfamiliar to me.

"Nightmare?" Me and y/n turned to follow that voice and saw classic sans.

"Classic." I said quietly.

"What are you doing here in my Au with, someone?" He asked as he looked at y/n.

"Hi! Classic, right? My name's Y/n. It's nice to finally meet you in person." She says as she let go of my hand --that made me slightly Disappointed-- and went towards to classic Sans and shook his hand.

"Heh uhh.. It's nice to meet you too y/n." He says with a calm smile. I growled lowly under my breathe whilst I glare at him. He looked at me amused. Y/n and him let go.

"So y/n, what are you and nightmare doing in my Au?" He asked.

"Well, me and nightmare are hanging out in your Au since I chose this place." She says happily.

"Oh. Well, I hope I'm disturbing not your date." He says. I slightly blushed on what classic says.

"W-what? N-no we're just hanging out. W-we're not dating." She says. 'yet.'

"Alright then." He says as he looked at the two of us.

"Welp," --he looked at y/n-- "I guess I should go now. I don't want to make your boyfriend mad for interupting your 'hangout' so, see you y/n." He says as he waved a goodbye for y/n. I slightly blushed from the word 'boyfriend' but shook it off. 'Y/n is just a friend in the past not my girlfriend. Well...yet.' I thought as my blush came back slightly visible.

"A-alright then, Bye Classic." She says ignoring the word 'boyfriend'. She walked towards me.

"Is classic always like that?" She asked as she hold my hand once again.

"Well, yes. He's like that sometimes." I said.

"Oh, okay." She says as she started to swing our hands slightly. She looks around.

"Hmm...A park! C'mon Crescent, Let's go to the park." She says as we started walking towards the park.

"Alright but why do we need to go to the park?" I said. It's about to be midnight.

"To see the sunset!" She says. She pulled me somewhere in the park and sat on the bench, I did the same.

"So, are we gonna wait here?"

"Well, I guess but not long." She says. Silence fills the place. She suddenly hummed another tune again. This time, it's quite familiar to me.
(A/n : You may play the song now! Also, the lyrics that have underlines means both you and nightmare are singing together.)

"Come little children,
I'll take thee away
into a land of Enchantment.
Come little children
the time's come to play,
Here in my garden of Shadows." She starts.

"Follow sweet children
I show thee the way,
Through all the pain and the sorrows.
Weep not poor children,
for life is this way,
Murdering beauty and passion." I joined in. She looked at me surprised.

"Are you, are you coming to the tree
They strung up a man,
they say who murdered three.
Strange things did happened here
No stranger would it be,
If we met at midnight
in the hanging tree." She smiled at me and continued as she closed her eyes again.

"Hush now dear Children
it must be this way,
to weary of life and deceptions.
Strange things did happened here
no stranger would it be,
If we met at midnight in the hanging tree. Into the calm and the quiet." Both of us sang at the end.

"Are you, are you coming to the tree."
"Through all the pain and the sorrow?"
"Strange things did happened here
no stranger would it be." "If we met at midnight in the hanging tree. Murdering beauty and passion."

"Strange things did happened here,
Weep not poor children
No stranger would it be
For life is this way,
If we met at midnight in the hanging tree.
Murdering beauty and passions."

"Are you, are you coming to the tree
Where dead man called out,
for his love to flee.
Come little children, the times come to play
Here in my garden of shadows."
"Come little children
I'll take thee away,
Into a land of enchantment." She once again, opened her eyes. We both looked in front seeing the sky painted in a red-orange color. The sun going down slowly it made me feel calm just the sight of the beauty. I watch it as the sun slowly goes down and darkness started to come in.

I suddenly felt something heavy on my shoulder. I looked to my right and saw y/n asleep on my shoulder. Her head was against my shoulder. I smiled. She is much more beautiful than the sunset nor sunrise. She was the light from my dark soul. She is my past friend whom I forgot and, I'm happy to see her once again. Y/n...why have I forgot about you? You truly are unique but, why did my past self made me forget you? I placed my hand on her shoulder holding her tight.

_______________________________________________________________

1892 words

That song is actually stuck in my head when I first heard it and tbh I think that song is somewhat a coincidence in my story plot-
(Well, some parts of the lyrics)

So, is this bonus chap good enough? Well, I'm  gonna add a few more cuz yess!

Finished typed in : June 14, 2019
Time Finished ; 10:47 pm(Philippine Time)

__________________________________________

—3rd pov—

As the night rises, Nightmare  carries the sleeping y/n up and teleported to her room. Placing her on the bed gently a small smile was shown on his face, he turns and was about to leave but a light tug stopped him from his tracks. He turned his head to see y/n pulling the edge of his jacket lightly.

"Please... stay.." she says softly as her eyes are getting heavy. Nightmare removed her hand on his jacket gently.
"Alright." He says which made y/n smiles in a sleepy manor. He lied beside her and p/n got out of the bed with a hiss to nightmare, leaving the two. Y/n falls asleep completely hugging nightmare. Nightmare's face was dusted with a blush but let it slide. He looks at y/n. Sweeping aside her hair, and placing it behind her ear. Nightmare smiles towards her.
"I don't know how you do it but, I love you y/n." He whispers as he closes his eyes.

_____________________________________________
2133 words

Yay I recycled this option as a bonus chap! Isn't this chapter cute? Owo

I enjoyed writing this and hope ya enjoyed reading this bonus chap!

Tho, I don't know when will I update the next chapter between the fight of y/n and gaster so.. be prepared on when I'll update :3

Anyway, see ya and have a safe and lovely day!

Finished edited in: August 1, 2020