Papyrus was just yelling at Sans as usual for being lazy as hell, before a portal suddenly appeared out of nowhere and sucked them in, causing them to end up in... the surface!? They were in a house.. it certainly wasn't they're house... before Sans suddenly noticed a mirror, he looked at Papyrus before realizing that he was... human... Sans looked at himself through the mirror, and saw he was human as well, Papyrus didnt realize it yet, so Sans grabbed Papyrus’s arm and made him look into the mirror to see him more humanized, they didn't realize that you, were in the same room as them having just woken up-