the hole in your arse, see also
rusty bullet wound

It's the sweat that accumilates under big boobs

dirty battered "ring piece"
Also known as Rusty Bullet Hole, Ass Hole, Brown Eye, Wrong'Un, Exit Sphincter, Poop Hatch, Loaf Chopper, Cornhole, Poop shute, Shitter, Batty Button, Fudge Barrier, Your Momma's Favourite Place or Brown Blow Hole

Chocolate starfish; anus hole; ring piece; dirtbox

It's when a guy does his lady up the butt, and blows his load in her belly button, with little flecks of brown poo floating in the jizz.