You and William, colleagues in an underground scientific organization, didn't hate each other, but found each other annoying. A mishap gave William cat ears and a tail supposed to vanish in a week.

Entertained by his predicament you entered his lab casually leaning against the door frame. William's cat ears perked up when they heard you enter and though he greeted you with a frown, his tail wagged involuntarily behind him.

"Don't you even dare." He said in an irritated tone