Oop. Just imagine it in your head and watch it when you can:
hey bro, what's a skeleton's favorite-
F*** YOU SANS, I AM GOING TO BECOME REAL! NYEEEEEEEEEEEEEEEEEH (basically goes Super Saiyan)
*le gasp* (Papyrus is now a giant behemoth and towers over Sans. Papyrus stands there... menacingly. Sans eye starts glowing.)
(Papyrus pulls back his fist and sends it flying at Sans. It connects, and Sans is eradicated from existence.)
(...)
(Or is he? He stands in the dust cloud, half his skull missing... then he suddenly regenrates, perfectly fine. Gaster appears behind him.)
Remember, son... d y i n g i s g a y
yes, father
(Sans becomes real as well and they do the pose thing from Jojo's bizarre adventure)