The Monster Inside Of Me (UF-Sans x Monster-Reader)

The truth

Narrator's POV

Diana's birth day is three days away. She will now be a 20 years old girl. Her mother, Toriel, is preparing for her birthday since a week ago.

"Mom?"

"Yes, my child?"

"Why you seem so busy and excited about my birthday? I mean, I never saw you this happy before, except for when you wrote something on Frisk's hand with that knife. Now that was something..."

"That, my child, is something you'll find at your birthday. I don't wanna spoil the surprise! I bet you'll love it!"

"Heh, if you say so..."

Diana then got out of the room, and went to Toriel's room, where she ussualy goes if Toriel hides something from her, and find out what it is.

She searched through her closet, desk, even checked her shoes, but nothing. She then threw a look at the bed, and spotted a box under it. She picked the box up, and read the words wrote on it:

Confidential:
Diana's data base!

She carefully opened the box, and took a piece a paper out of it. On the paper was written:

This little girl's name is Diana, and she is two years old. She will be three in exacly three days away from today. She has got a curse from an unknown person who reached her in an unknown way. I have been informed that other people will now hunt her, and my mother strength is not enough to protect her. I know that there is someone in that Ebott mountain, someone who will listen to me, and take care of my daughter!
About the curse, at the time she will turn twenty, she will become a monster. Please don't let her know about this, and raise her as your own child.

Diana's natural mother...

Diana's POV

I,... I felt so lied, so... alone. I can't believe I never found this before.
I wanted to immediately go and talk with Toriel about this, but I thought, maybe talking to my closest friend will help me calm down a little and then I should talk to mom.

"Hey, mom? Can I go see Sans?"

"Of course you can! Just, please don't talk to other monsters and watch out for Asgore, will you?"

"Yes, you told me that like one hundred times before!"

"I am aware of that, but I don't want you to forget it!"

"I won't, I promise!"

I hugged her, than I ran, as fast as my legs could, to the skele bros house.

Sans' POV

I was sleeping on the couch, than I woke up with a Papyrus screaming at me.

"SANS! SOMEONE IS AT THE FREAKING DOOR! MAKE YOURSELF USEFUL AND GO SEE WHO IT IS, YOU LAZY ASS!"

"Why don't you prove that you're not the lazy ass here?"

"DID YOU SAY SOMETHING?"

"ERM No I didn't, I'm gonna go see who's at the door *sigh*..."

I lazily woke up from the couch and went towards the door. The person on the other side of it kept knocking again and again and again.

"FUCK OFF!"

Than I opened and saw Diana standing there.

"Oh, Diana! Sorry about that... Come in, please!"

I noticed that she was sad? Depressed? I don't know which one!

"Sans, ..." She said in a shy tone.

"Sup kid? You don't seem in your bones today!"

"I have a stupid question for ya... You'll probably think its nonsense. You'll remain my friend, even if I'll change?"

"Change?"

I knew EXACLY what she was talking about. Did Toriel told her?

"She ... Toriel... Told you?"

"You knew about it?"

"I ... Umm... Yes, I did"

Some tears than falled from her cheeks.

"Sans, I'm scared" she said, jumping towards me and hugging me tight. "What if I wont be a monster just on the outside, but on the inside too? What if..."

I then interrupted her, placing a hand on her back and the other hand on her head.

"Shh calm down,... Everything is going to be fine. You won't change that much! You'll remain the Diana I always l-"

I then stopped, realizing what I almost said.

"Were you going to say..."

"l......lliked and appreciated. The one who showed what it means to be someone who is not alone.

"Y-you really think t-that of me?"

"No, I KNOW that about you. If it wasn't for you, I would still be outside helping my brother to kill other monsters. You know, Underfell is a different place since you came, a-and I like it"

She than looked me in the eyes (sockets?).

"Sans, are you blushing?"