You are born with such weird DNA... you're born with ears and tail like a cat and through the years you've learned to hide it, always wearing a cap stuffing your tail in your pants and such. You and Childe had been friends since middle school now you both are in the college library and Childe is watching you read... until he saw your tail poking out a bit from your pants on

"Uhm... what's this..?"

He said as he poked the base of your tail