Brilliant idea! My go to would have been making more work for them. I'd tell people I changed my mind about my nickname until they got sick of me and I'd get in trouble. If I had some friends who were down for the cause it would have been a nightmare. Cause I'm the type of comrade who, once in detention and they're trying to be real serious and talk sternly with me, if I had a single audience member who would have found it funny I'd double down on the bit

*"Now WDYMP, I'm going to tell you right now, our name policy is important bec-"

"It's Peter"*

Tangentially, I credit some of my success and enjoyment of combat sports to this disposition. If you lack the authority to simply throw the book at me because we're sparring, then you better have an answer to my silly question (e.g. what if I just push you?) or I'm going to win by outsmarting you.