The thin roll of left-over toilet paper that develops when a moist or dry coochie is wiped with toilet paper and is stuck in a coochie crease. It will typically dry up and fall in panty liner. Not uncommon to be be seen by personal wax lady. It happens most often with 2-ply toilet paper.
"Damn girl, that pussy be smokin'. Look at all those coochie joints."
"Hey babe, do I have cotton mouth? Or is it your coochie joint."
"I asked my wax lady, are those white pubes on that wax strip. She said, no, those are your coochie joints."