I was wondering this today:
What would you do if you saw someone your age diapered? Would you confront them about it or would you never bring it up? If you were to confront them, would it be directly or indirectly? Would the sex of the person matter?
Personally, if I saw someone my age in diapers, I would probably never bring it up. However, I might bring it up indirectly if the person in question was a girl I was interested in, but in all likelyness I would probably let her talk first. For me, gender matters. I would never confront a dude about diapers.