P-hub fallacy
You're so full of yourself that you think you're the only one who does stupid stuff, but you're just as dumb as the person you're talking to.
"You're cheating on your math test?" I said. Then I remembered I had a cheat sheet under my desk.
"You're sneaking out at midnight?" I said. Then I remembered I was wearing my pajamas and had a flashlight in my hand.
"You're texting in class?" I said. Then I remembered I had my phone out too."