I took a statistics for psychology midterm last semester, and the room I was writing in was boiling hot, so I took off my hoodie while writing the exam. I went to the front of the room to hand it in to the prof, and he furrowed his eyebrows as I did so, but I figured it was just because I was the first one to hand it in and he'd figured I'd given up instead of completing it. I was still warm, so I walked home without putting my hoodie back on, and received a few more odd looks on the way home.
It wasn't until I got to my apartment, that I realized the shirt I was wearing underneath was completely translucent. I had inadvertently shown my middle-aged professor (not to mention those in the class who may have looked up from their exams, and everyone i passed in the street) my neon blue, black-polka dotted push-up bra (with various bows and ribbons) and my dice navel ring.