Unhinged

Sadie watched Sally as the professors kept talking. While Sadie’s eyes were filled with tears, Sally was clear-eyed, sitting there like nothing was wrong.
Instead of sitting with her legs tucked together as a lady should, she sat with her knees as wide as possible.
She was dressed in cargo shorts instead of a respectable dress, loudly chewing her gum. How could she be so unhinged at a time like this?