What Cassidy indeed wants here is to appall or turn Adrian off just like what he has guessed, but when he suddenly starts boasting his wealth instead, she feels like she has been cheated on.
The overwhelming amount of confidence that he's displaying at this very moment somehow terrifies her. Sure, he appears like a big-headed idiotic foe whose smug face she badly wants to wipe off. But it can also mean that he's more than certain that spending a million everyday will not be a burden to their finances.
Despite her own claims, she's not really a materialistic person. Shopping everyday for no good reason will only end up stressing her out. She knows she can't take up that challenge unless she wants to waste millions for real, which she really doesn't want to.
"Hey, I know you're crazy rich, but you can't possibly be that rich!" Cassidy exclaimed while inching her face closer to his and furrowing her brows in annoyance.
