There is no reason for you to be sorry for your question, we are happy to provide you with the answers.
I will try to explain the significance of "Mormon underwear":
A member of the Church of Jesus Christ of Latter Day Saints (commonly called "Mormons") who has been endowed in the temple (being endowed means that you have made certain covenants with God in the temple) will wear special undergarments (called 'garments' by church members) to remind them of the covenants they have made. This is similar to the way wearing a wedding ring reminds one of the covenant or promise they have with their spouse.
Many other denominations and religions have special robes or other clothing for their clergy which worn outwardly during ceremonies/services, and since Mormons have an all lay (unpaid) clergy, the garment is a sort of 'priestly robe', but worn under our clothing. It is considered sacred and is not discussed in casual conversation. If it is mocked or disrespected it is very offensive to faithful Church members.
The Church published reference book, True to the Faith, says "Once you are endowed, you have the blessing of wearing the temple garment throughout your life... The garment provides a constant reminder of the covenants you have made in the temple. You should treat it with respect at all times. You should not expose it to the view of those who do not understand its significance, and you should not adjust it to accommodate different styles of clothing... Wearing the garment is an outward expression of an inward commitment to follow the Savior."
I hope that this answers your question and if not please let me know and I will try again.
Oh..and welcome to the forum!
