I added a translation note to Cirno's first line. Couldn't figure out a good way to translate the pun, so I left it as Tobi-sempai translated it for now, since it flows well.
Everyone in the comic are fucking spiteful assholes ( except Cirno )
GAH! You shall not cross this bridge. You son of a bitch! You're pretty cheeky for a damn moron!I already knew that! A bridge's no good if you only cross halfway, LOL! The pun here is はし can mean bridge, 橋 or edge, 端. Cirno thinks Parsee is saying the edges of the bridge are no good, so she'll go right down the middle.