Susie thinks different colored chalks have different flavours cuz Kris told her that (after they became friends) since its canon that Kris is a prankster

underchara:

She tries it and goes “holy shit they actually do!!!” And Kris is like “??????????that wasn’t supposed to???” And then Susie offers them one of the colored chalks and Kris takes a bite out of curiosity

It just tastes like chalk. She tricked them into eating chalk again.

Susie is losing her shit