In case you can't tell, this is "All I want for Christmas is You" sung by Papyrus and Sans https://www.youtube.com/watch?v=oflFgOYyeoU
I looked up "Papyrus Playlist" Because I wanted to find every song with the Nyeh heh heh motif, and I stumbled upon this... Gold? Maybe Pyrite... There was also a comment that I'm going to steal that perfectly sums this up: "Papyrus: *Me Singing in the Shower*, Sans: *Me Singing in a School Play*" -@VinNNySK This is why Papyrus is my favorite Undertale character.
