muddy shark
(n.) A sex move whereby one partner inserts the index and middle fingers into the female's vagina while simultaneously inserting the ring and pinky fingers into the female's anus, thereby forming a shark-like hand puppet with a muddy lower jaw. More simply, "two in the pink, two in the stink."
After becoming bored with traditional fingering techniques, the couple moved on to more experimental options such as "twister," "twisted shocker," and eventually the "muddy shark."
muddy shark by Soggy Bobby August 7, 2011