If you were an aunt and you noticed your nephew was wearing womens?
If I were an aunt with no legal responsibility for my nephew and I became aware that he was wearing womens underwear I would say nothing to him or legal guardian. If I were an aunt with legal custody of my nephew the situation would be different. I would speak to the nephew about his liking for womens underwear, but I would not punish him nor stop him. In addition, I would also say nothing to anyone else about my nephews use of womens underwear. As to what I would say that would depend on my nephews willingness to talk about the subject.