AU Undertale x Reader Oneshots [DISCONTINUED]

child!UF!Sans, UF!Gaster, child!UF!Papyrus x motherly!reader (part 1)

Two months had passed since that fight, and you never crossed Gaster again. Despite your tough spirit, you were terrified, while staring into the face of death. Gaster has been coming up to watch you and his sons more often. He would stand near the stairs and watch as you taught them things.
Today, you didn't notice him there as you were teaching Papyrus to speak. 

"Can you say 'dad'?" You asked Papyrus. He tilted his head and tried to repeat what you said. Gaster was shocked that you weren't trying teaching him to say 'mom' or 'mama'. "D... dah... dada?" Papyrus tried to say. "There we go!" You praised, giving him a pat on the head. "Good job!" You praised. "Now when your dad gets up here, we can surprise him." 

"So that's why you were teaching him the word 'dad' instead of mom'." Gaster said, startling you. "You wanted to surprise me?" You looked over and saw him standing by the stairs. You tried to find some words to say, but just nodded instead. "I wanted to surprise you with his intelligence." you said. "Papyrus is very smart for learning words this early." "And what about Sans?" He asked. "He is three years old. Has he learned any words, besides gibberish?" "He has." you said, giving Sans a little nudge towards his dad. "Go on, Sans." He lowered his head, and looked up to his dad. Then he took a deep breath and said, "My name is Sans Gasteh, and my dad is a vewy smaht person name Doctow Gasteh, and my mama is name (y/n)."

Your eyes widened when Sans called you his mom. "Did he... just call you his mom?" Gaster said, standing up straight and walking up to his son. "I didn't teach him that." you said, holding up your hands in surrender. "Then how else did he learn it?" He asked, picking up Sans and looking at you. "I-I don't know." you said. "From you maybe? Because I don't recall ever saying the word 'mom' in front of them." "Mama!" Papyrus squealed, then you felt him grab your leg. You looked down and saw him hugging your leg. Gaster furrowed his brow at you. "It must be from when we had that fight two months ago." he said. "Must be." you said, picking Papyrus up. He smiled and nuzzled his head against your chest.

"How about you prepare some food for them?" Gaster suggested. "I-I'll watch them until you're done." You saw a red light dust his cheekbones. You were surprised he was the one to suggest this. "O-Okay." you said, handing the skeleton to his dad. 
You walked into the kitchen and started preparing some sandwiches for you, Gaster, and the two kids.

Later that night, after you went home from taking care of Sans and Papyrus, you woke up from your deep slumber to the sound of your phone ringing. You yawned, and got up to answer the phone.
"Hello?" You said, holding the phone to your ear. "(Y/n)? Is that you?" A voice said. It sounded like Mr. Gaster, and you heard crying in the background. "Mr. Gaster?" You asked. "Yes, it's me, (y/n)." he said. "What's going on?" You asked. "Sans and Papyrus had are afraid of the storm, and I don't know what the hell to do." he said. "I need you to come over and help me." You face-palmed, but agreed to come over.

You drove over to his house in the rain, and knocked on the door. You heard the cries of the poor children come closer to the door, and it opened to reveal a very tired looking Gaster, with two sobbing little skeletons in his arms. You walked in, and right when the door shut, the thunder boomed, making the children scream in fear and cling to their dad. "Make it stop!" Sans cried. "Dada pwease!" Papyrus pleaded, sobbing into his dad's pajamas. You were absolutely heartbroken at the sight. 

He brought you up to his room and set them on the bed. They crawled up to one another and held onto each other as they shook and cried. You sat down on the bed and lifted the two of them onto your lap. They looked up to see you, then they wrapped their arms around your stomach. "Mama!" Papyrus cried. "Mommy, make the noise go away!" Sans sobbed. You wrapped the two of them in your arms. "It's okay, little ones." you said, rubbing their spines. "It's just a noise. Noise can't hurt you while me and your dad are here." That didn't stop crying. 

"Hold Sans." you said, handing Sans to Gaster. "For what reason?" He asked. "Just trust me." you said, then you proceeded to rock Papyrus in your arms, and sang a lullaby.

Come stop your crying, it will be alright.
Just take my hand. Hold it tight.
I will protect you from all around you.
I will be here, don't you cry.

Sans and Papyrus started to stop crying, and lean into your touch, and Gaster's touch.

For one so small, you seem so strong.
My arms will hold you, keep you safe and warm.
This bond between us can't be broken.
I will be here, don't you cry.

Gaster sighed as he held his tired son against his chest. Sans snuggled into the warmth coming from his father's soul. Gaster could feel the links he had with his sons now.

'Cause you'll be in my heart.
Yes, you'll be in my heart.
From this day on. Now and forever more.

Gaster smiled and began to sing with you.

You'll be in my heart.
No matter what they say.
You'll be here in my heart.
Always. 

Then you whispered,  "Always." in Gaster's ear. He looked down at you as you leaned against him, cradling Papyrus as he slept. "They will always remember this lullaby." you whispered so you wouldn't wake them up. 
Gaster pulled one arm out from under Sans without waking him, then he wrapped it around your shoulders and held you close to him.
The four of you stayed together for the rest of the night.

~A/N~ I hope you enjoyed! I'll upload part 2 as soon as I can