What if? (Sans x Reader)

What if a computer that has been hacked by a great scientist glitches and makes video games come to life? The scientist gives this computer to one of her best helpers, (y/n), as a 'prize' for her birthday. Two years later the computer started to glitch while (y/n)'s best friend was using it, playing a video game, and out of no where a certain skeleton appears...

I don't own Undertale or any of the characters.
I give partial of my credit to @Vonique12 who wrote this with me.