I think there's a subgenre of p0rn for everything, the creativity of the human sexual drive has no limits.
Mormon do have magic underpants, so it's possible, though I don't know many Mormons, and none well enough to have seen them undressed. I don't think you can just ask for a show and tell. I think a colleague of mine is a Mormon, she's from and lives in Utah, and is very nice though she's a slow-talker*. HR will be pleased to know that I've never asked what she's wearing under her dress.
*I actually like this, she just talks so slow, every sentence is like the passing of one of those long US freight trains, the words keep passing by and she never gets any faster, and once she's launched a sentence, you can't stop her, she will finish that sentence, even if – and it probably will – take until next Wednesday.