that one scene where sans drinks an entire bottle of ketchup

Sans drinking ketchup, while Frisk looks on confused.

sans misses papyrus so he drinks ketchup

Genocide Sans drinks to forget the loss of his brother

sans holding papyrus' scarf while crying and drinking ketchup.

sans is sad because chara killed sans, he stains papyrus' scarf red with ketchup

sans throws ketchup at papyrus cause he's sad chara killed him. papyrus is annoyed. not again, sans

sans wants to protect his precious brother from chara by throwing a bottle of ketchup at his face.

sans stopping papyrus from sparing you in a genocide run by throwing a ketchup bottle at him