You seewhat they wear by the 'marks' they live it in the body..they are tongues..or small brasilian style biquinis...

For sure i will not wear one of those in public places...in the USA..but in Brasil and Europe..for sure I would...

I wear here decent ones that covers my butt but i hate the big marks they let in my body...the bum is too much white for my personal taste..than i try to not suntan much in those...or when is possible stick some extra biquini lycra inside the butt...