Similar to a pink sock, but better. While giving the girl anal the man punches the girl powerfully with both fists in both kidneys. AS she tenses up her anus, the man thrusts as hard as possible, causing her to fly off the man's cock. This inadvertantly causes the girl to pink sock herself.
'Did you pink sock that bitch?'
'No man, I fuckin' kidney krunched that bitch so hard she's still bleeding.'