Underfell Sans x Reader x Undertale Sans

Strange night....

~Reader's P.O.V~

I was on my way to Sans and Pap's house for our movie night. Honestly, I do admit. For a pun loving skeleton like him, he sure is cute...hehe, i love it when we spend time. Oh well..it isn't like he likes me anyway, right? No way! Heh...we're just friends...but hey! You can't blame me for liking him anyway! Anyway, I was walking to the house and I notice the lights were still on so I guess they're home. I knock on the door once and it just opens, "what the...pfft...sans, that lazy dork forgot to lock and close the door properly...wait...but even so...." I trail off, knowing even if sans wasn't closing the door, Pap's would of done it for him...hm. Something was off here. I open the door and walk in, glancing around. It's empty...no sound of Pap's loud voice, no snorting of puns, no sizzling from Pap's cooking....just silence...I walk to sans room, and well...I know it's rude, but I do it anyway. And the moment I opened it, there was nothing...just that stupidly weird tornado in his room, always messing his room up. And as I look at his bed, there was a note. 'Strange, he's usually to lazy to even write sometimes. This must be somewhat special. ', I think to myself and I grab the letter, closing the door behind me and reading the letter.

It reads,

"hey, (Y/N).

I know, I know. Why aren't I there with ya? Hanging out with the most awesome girl I've known since I met her at the park? Well. The answer to that is simple, kiddo. It's cuz I'm busy goin' with Pap's, undyne, and Alph to frisk's performance. I'll talk to ya later, if I can, kiddo. By the way...I'm saving my hilarious puns for later, tibia honest. Opps, had to let that one slide. Hehe, sorry.

From, Sans."

I felt kind of sad that we don't get to hang out. But on the other hand, I get to make some food for us and probably explore around his home! I know, it's bad...but it's cool, I'be never been in his house, other then Pap's room, his room, the kitchen, the bathroom, and the living room. ' I wonder what his basement looks like... ' I think to myself as I smirk, getting an idea like the dare devil that I am. I leave the note on his bed and I run out, going down the stairs and pass the living room, seeing the basement door as I pass the bathroom...'gosh, I'm so excited!!' I think and I grab the handle, slowly turning it and I slowly push the door, feeling my sins crawl up my back for this...its worth it though!...'wait, what's this?' I ask myself and I saw a little tube-like thingy....I go up to a near by desk with tons of illustrations. The one in blue shows the tube like thing. It says, " Alternate Universal Portal" I read aloud and continue, "Hopping from AU to AU, a gift given from Core! Frisk. Thanks to them, I can actually see my own Alternate selfs...what?" I ask, feeling confused of why or who even wrote this. Could it be Gaster? No...Gaster can't be here for this...but it could never be sans. He's too lazy to ever make anything like this or get contact from something like this. All of the confusion was knocking my brain, I felt dizzy..."W-Woah....what-- ugh, my brain..." I mutter as I stumble around, hitting something and I fall into the tube thing. I gasp as I saw light flash before me,

"TRANSPORTING TO..." The machine calls out, I quickly try to get up but by the time I did that, the door closed on me, locking me in.

"LOAD COMEPLETE. WELCOME, SANS CLASSIC, TO UNDERFELL." The machine calls out and I cry, banging onto the door, wanting to get out. But there was no way out. 'What the hell am I to do?!' I cry out in my mind as I black out, only seeing a flash of red and black before I passed out onto what somewhat felt like flowers....oh no....

.... W h a t  H a v e  I  D o n e ?