Labia thong
It's a thong that doesn't go between your butt cheeks it goes between your outer and inner lips like it's trying to sneak into your secret hideout.
My mom said she wore one to a yoga class and the instructor thought she was doing a new pose.
My dog ran into me wearing one and he looked like he was about to bark a curse.
My brother tried one on and said it felt like his pants were giving him a wedgie from the inside.