Self-Admitted Thief

Today in 4th period science, some of the students were trying to figure out my first and last name. I always write "Mr. G." on the board so I don' have to hear the repeated butchering of my last name - Gantenbein. I told the group I was talking to that if they guess my last name, I'd tell them they got it right. After a bit I walked to another table group to answer a question. 30 seconds passed by when then came back to the teacher's desk and sat down. I was filling out a hall pass for a student when two students, Eric and David, came over saying, "Andrew how do you say your last name?" I didn't initially think they were talking to me but then realized they somehow found out my middle name and were trying to see if I'd respond to it (they thought it was my first name). I wanted to know how they figured out my middle name since I don't have a name tag or anything.

Me: "That's not my name."
David: "Yes it is."
Me: "How do you know?"
David: "I looked in your wallet."
Me: "What! Well go ahead and take a walk to the office. You don't go people's personal stuff like wallets. Seriously go to the office."

He was in shock since his intentions weren't bad, but just thought it would be a good way to find out my name. Then Eric and a few others started laughing at him saying, "you just told on yourself. You deserve to go to the office." He couldn't really look up, he was so embarrassed, having realized he just told a teacher that he had been going through their wallet. Eventually I said, "David, you don't have to go to the office, but don't ever go through my crap." He nodded. The heckling continued. Then I thought what a great story this would make and I definitely needed a picture of him. I took about 90 seconds for him to be able to look at the camera (I told him I'd give him a referral for looking through my wallet if he didn't let me take a picture, but I wasn't serious). So here he is, in all his genius: