Undertale AU Sans x Reader Oneshots

NaJ! Nightmare! x Female! Neko! Teacher! Reader

(You are wearing a (F/C) long sleeve shirt. A skirt that reaches to your knees. It is the same color as your shirt but the skirt is darker. Matching flats and a (F/C) scarf with white stripes. You can change the outfit if you don't like it.)

(Y/N) POV
I was grading the book reports my students gave me. They were all amazing so far. My ear then twitches. I didn't look up I still kept grading. "You can come in." I said. I then hear footsteps come near my desk. I look up and see one of my very good friends, Nightmare. "Hey." I wave at him. He smiles. "Hi, how you doing?" He asks with a funny voice. I flatten my ears a bit and giggle. Nightmare is one of my very good friends but my best friend is Cotton Candy. "I'm fine just grading book reports." I then look at the clock. I then look back at Nightmare. "You work to hard. At least use your break." Nightmare says. Come to think of it I haven't had a break for awhile now since I'm always grading work. "Ok." I get up and walk towards Nightmare and we leave the Literature/LA room. I'm the Literature teacher as well as Language Arts teacher.

Nightmare and I walk in halls together. "How's your relationship with Muffet doing?" I look at Nightmare. He sighs. "Tough." He says and then stays silent. Something tells me the 'tough times' is personal. Therefore I won't ask about it. "Is your class ok?" I said trying to change the subject. He starts to chuckle. At least he is now in a happy mood. "They are really funny especially when they find out they have to do a huge assignment." Nightmare really loves surprising people, especially his students. I start to wag my tail side to side. I then feel Nightmare's hands scratching the back of my ear. I start to purr. "Meow~" My tail starts to wag faster. I hate it when he does this but it feels nice. I then get back to reality. "Stop it Nightmare." I said in a baby voice. He starts to laugh and has a purple blush. I blush too. What am I doing?! He is already taken. I start to calm down. We then start to chat. I then remember the reports. "Oh Nightmare I have to finish the reports. It was nice hanging out with you. See you later." I start to head to my classroom. I then start to get to work.

I actually finish earlier than expected. It is like 4:00pm. I grab my coat and bag. I walk out of the classroom and then I see Cotton Candy. He is my best friend. I walk up to him. "CC!" I shout. He immediately smiles. I gave him that nickname. We then start to chat.

Nightmare's POV
I was reading a book in the office. I then start to hear footsteps. I ignore them but then a figure is casting a shadow over me. I look up to see Muffet. "Hey baby." I smile at her. She did not look happy. I was confused. "You ok?" I place the book down and stand up. She still looks angry. "Why were you doing that?" She asked. I raise a bone brow. "What are you talking about?" She then looks furious. "Don't play dumb!" She yells at me. I was taken back from her yelling. She rarely yells at me or anyone in general. I was still so confused. "I'm very lost right now." I said in all honesty. She then widens her eyes in anger and slaps me.

I then look at her with anger as well. "Well I'll be leaving." I said trying not to yell. I grab my book and keys. I leave the office and head out the door until I felt my arm being pulled. I look back and see Muffet still angry with me. "Why'd you pet (Y/N)!?" She yells at me. I raise a brow once again. "Is that why you are angry?" I said with anger and confusion. She nods and crosses her arms waiting for me to answer her. Then realization hit me in the face. "Muffet we are just friends." I said trying defend myself and (Y/N). She then rolls her multiple eyes. "Yeah right you probably are secretly dating her maybe even sleeping with her." She says with a snotty way. I start to get enraged. "I'm not cheating on you!" I yelled at her. She shakes her head. "You're a liar." She says giving me a dirty glare. I start to get furious. "Says the one that is sleeping with one of my best friends, Grillby." She then widens her eyes with shock. I already knew she was cheating on me but I still love her so I never confronted her. "Yeah I was there in the house when you started to get busy. Looks to me you're not very loyal while I was during our 3 year long relationship." She then opens her mouth but nothing came out.