Diana was given one today for the 'thing.'
I had to explain that the first time I ever even saw one was in "Crocodile Dundee" when that girl goes to wash her stuff in the water, and she's wearing a thong bodysuit.
Until then, I don't think I'd ever seen one.
In the 70's, we wore Dittos jeans, but I don't think the thong was invented until after I was in high school. I did know girls that just 'went without' or wore Underalls so they wouldn't have panty lines.
Thong underwear didn't come into being until the 1990's according to Wikipedia.
She was supposed to try on dresses for Prom today. I don't know if the underwear was needed for a slinky dress or what.
I think the gals were surprised at Diana's reaction.