Danny wants to point out that no one would have been paying attention if they'd just kept to his whispered volume, but now that she's plainly talking, of course everyone is going to know that they know each other. But winning that pedantic battle is not his number one priority here.

"How did you--that invite was for me! Which is why it said "Dear Cure Phantom" on it? That means not you!"

He isn't sure if he's more worried or angry right now.