Undyne x Female reader

Chapter 1: The chat

~(Y/N)'s POV~
"Sooo Sans made a joke about a guard and got in a fight with the guard's girlfriend?" I asked Frisk trying to under stand what he's trying to show with her hands (maybe a him but I'm going for her for right now). Frisk nodded and took a drink of her apple juice with a smile. "Wow I feel bad for Sans. Did he win?" I ask and Frisk shrugged "also, were do you get apple juice? Do they even have trees with apples?" I asked and she shrugged. "Hey kiddos!" We hear Sans say behind me. I spun around surprised and Sans laughed "sorry I didn't mean to scare you" Sans said and I smile "it's ok" I said and took a drink of water "so why are you here?" I ask tilting my head to the side "well Undyne is looking for you actually. She said she needed to talk to you" Sans said "speaking of which I have to tell her that your here. Be right back!" Sans said and teleports away. I look at Frisk "should I run?" I ask and Frisk nods. I quickly jolted out of my seat and ran outside with my coat on. I was running towards the house where I shared with Sans and Papyrus. "Please don't be here please don't be here please don't be here" I repeated over and over again. I opened the door to see no one inside and I sighed in relief. I closed the door and turned on the lights. I see Sans teleport to the house and teleports away. "That was weird" I mumbled and sat on the couch. The door suddenly swung open and I jumped. Undyne ran towards me and gripped my shoulders. I flinched "(Y/N) why are you running away from me?" She asked sternly "w-well I thought you are mad at me for some reason cuz ever since I've been here the only time you show that your mad in public is by searching for me until you find me alone sooo ya..." I said and she grinned "well not this time. This time I have to tell you something or more like ask" Undyne said "Ok? What is it?" I asked "will you like being trained as a royal guard by me?" My eyes lit up "of course!" I yelled and Undyne giggled. "Good. Also, all you need to do is learn how to fight cuz well....you already have a six pack" Undyne said looking down on my showing abs (yes you have abs in this. If you don't have abs then pretend you do in here) since I was wearing a thin black tank top. I blushed and covered my abs "no staring!" I scolded and she chuckled "aw c'mon kid! Just one little look?" Undyne asked with a little bit of puppy eyes. I flinch and blush more "YOU ARE NOT MY GIRLFRIEND!" "Aw darn" Undyne stood up "well anyways you might want to go back to Frisk. She seems sorta bored when you left" Undyne said and I nodded. I went to my room to get changed and walked back downstairs to see Undyne already gone. I shrugged it off and ran out of the house towards the little bar like place were me and Frisk were. I walked in and sat in front of a lonely Frisk. Frisk smiled "sorry I left Frisk. I thought Undyne was mad at me or something...." I said smiling awkwardly while rubbing my neck and Frisk gave me a thumbs up with a smile. We talked until Serphina, my best friend (also OC of mine), came in and shook off the snow that was covering her. She walked over to us and pulled down her scarf "hey (Y/N). Hey Frisk" Serphina said in her emotionless voice while pulling up a chair and sitting down. "Hey Serphina!" I greeted and Frisk gave her a little wave "so what brings someone like you here? I don't think you drink" Serphina looked at me and raised an eyebrow "oh so you two are drinking?" Serphina asked and we shook our heads furiously. Serphina smirked "good" Serphina said and a waiter came over and took Serphina's and mine order. "So Frisk can you tell us about how you defeated Undyne in the first try?" I asked and Frisk nods and starts telling us how he defeated Undyne. "Wow Undyne might seem like a threat but loosing to Frisk? It sorta makes her weak ya know?" Serphina said and I punched her arm "don't be rude! She is a threat! You go try and beat her!" I said angrily "ok! Ok! I'm sorry that I insulted your crush!" Serphina said putting her hands up in defeat and I blush "don't say that out loud!" I whispered yelled, calming down "sorry" Serphina whispers back. 'Wait so (Y/n) has a crush on Undyne?' Frisk translated and Serphina nods while I look away blushing "ok anyways! How do you feel about everyone Frisk?" Serphina asked changing the subject 'Well Sans is pretty chill and cool and loves to make puns even though most of them are bad, Papyrus can sometimes be scary but he's actually nice once your on his good side, Alphy is shy and love making potions and help people, and Undyne is flirty, strong, scary, and loves calling me and (Y/N) kid or kiddo' Frisk translated "what about everyone else?" I ask tilting my head a little to the side "yea! What about me?!" Serphina said being dramatic 'we would be here until midnight' Frisk translated "wow. How many people do you?!" I ask 'a lot'.
~2 hours later~
We chatted for about 2 hours and it was about 11:00. "I have to go. It's 11:00 and I have training with Undyne" I said and Serphina smirked "so your training with your girlfriend huh? Since when?" Serphina joked "She isn't my girlfriend! Anyways, she asked me when I ran to my house to hide from Undyne when I thought she was mad at me" I explained and I blushed more 'what happened?' Frisk asked with a smirk and I blush more "well she asked me and she said I was fit enough because of my abs a-and....." I trailed off and my face became a tomato "aaand?~" Serphina asked "a-and she wanted to look at my abs" I whispered but they still heard it "haha! That's what you get for being so shy! You give in easily most of the time!" Serphina said and I stood "w-well Bye!" I said dashing to the door "bye bye!" Serphina said. This is gonna be interesting I thought.