butt bridge 

The chunk of skin that is used as a bridge between a males scrotum and butt hole, or females pussy and butt hole.

My butt bridge got stained a tinted brown after a bad day of diarrhea.

butt bridge by Dendog LXIX January 11, 2018

Butt Hair Bridge 

When hair from around the Anus connects between the butt cheeks, therefore manufacturing a so-called bridge. Sitting down or scratching the Anus, usually destroys the bridge.

Thought I got bite by an ant or something, turns out another Butt Hair Bridge(BHB)was being constructed.

Butt Hair Bridge by Reverse Learn April 27, 2009