Rubbish, it doesn't matter what you wear under the kilt. I have always worn it regimental - to weddings, conferrings, formal dinners, etc. The advantage is that you stay comfortable. Unless you are competing in dancing or participating in highland games, you do not need underwear. In any event, even if you did wear it to church, who is going to ask you to let you inspect what is underneath it???

Niblox