my deskmate put a name sticker i gave him on his phone case and made it his profile pic

so my deskmate is a guy right, and i was putting those new sticker-style name labels on my notebooks and textbooks. you know the ones? anyway i'm just slapping them on and he asks me for one. one. singular sticker. i thought maybe he wanted to put it on his clothes or whatever but NOPE. this man puts it on the back of his phone case. and THEN. he takes a mirror selfie with it, makes it his kakao profile picture, and my ENTIRE NAME is just. visible. crystal clear. three characters just sitting there for the world to see i'm actually dying like what is he doing???