Xingu Indian girls nude and non-nude

I am not a specialist of the Amazon tribes history and culture, but what I know is the fact that Xingu Indian girls which walk around nude as they are seen by tourists and other visitors, are actually not nude. Because they wear waist belt (uluri) which have a small ribbon going from waist stomach part to the back between legs and through pussy. This ribbon actually "closes" girls genitals and these Xingu Indian girls who wear waist belt are not able to have sexual relations. Therefore they don't even have any shame because according their own traditions these girls are "clothed".
Anyway it seems like due to the growing amount of tourists some girls have realized that visitors see them as nude and as you see in this pic: https://xhamster.help/photos/gallery/14193661/398336252 two girls cover theyr pussy with hands and only girl in right is "genuine" Xingu Indian girl who is proud of their traditions. You can also see like one probably European girl ties Xingu clothing and she looks happy because she is not nude! https://xhamster.help/photos/gallery/14193661/398336596 It means she can show herself basically nude but she can say all to her friends or relatives, that this is not what you see, I wear actually a waist belt!
And finally in this pic you can see Xingu girls actually nude: https://xhamster.help/photos/gallery/14193661/398336131 I don't know maybe these two girls broke the rules by posing nude or maybe they are not Xingu Indians but paid models. They look by face as Indians, but plenty of bracelets and necklace hints that maybe they are just girls from Brazilian village, similar to Indians and they pose nude.