Recently I was asked a question during astronomy lab that I hadn't been asked before: "Does this look like porn to you?" Upon this utterance, a black-and-white image of a naked woman, kneeling on a bed with her arms above her head facing the camera, was shown to me. I'm proud to say that I didn't blush, but said, "I could see how some may call it pornographic." Then the student asked, "How about these?" He then showed me more images of the same woman, naked still, but in more chaste poses. Turns out that this was part of an assignment for a photography class, and he had been upset that the instructor deemed them porn rather than art. This led to a very good discussion about pornographic material versus obscene material, whether or not his instructor should be making such distinctions, and questions he could ask himself about his work if he was worried about offending classmates.
But still... it was a different experience that I usually have during astronomy lab.