I'm going to post a random story, so I can add random chapters when the urge to write hits me.
"A masquerade ball?"
"Yup."
"Where everyone wears masks?"
"Yup."
"Why?"
"Because," Aang says excitedly, "it's fun! And so people can dance with others not worrying about appearances!"
The blind girl raises a mocking eyesbrow. "Not worry about appearances?"
"Yeah! You can really get to know people, and you can't recognise them at all, so if you mess up, nobody knows it's you!"
"I think it's pointless."
"Pointless?"
"To me, anyway."
"What! Why?"
She snorts, flicks him in the head and walks away, laughing to herself.
Only minutes after she's gone, does Aang realise his mistake.
It just makes him feel like a fool.
Because Toph going to a masquerade ball would be pointless. She can't see, and she reads vibrations, so she'll know who everybody is, anyway!