It's when you grab your scrotum in such a way as to constrict and expose the testicles so that they may resemble a tomato while your partner then proceeds to "polish" the "tomato" be it with tongue, appendage, feather, etc., etc..
Nickname given to bales of marijuana thrown overboard or out of airplanes. Origin is reportedly from members of the US Coast Guard in the area of Southern Florida.
"Base we've got some square groupers floating outside of Miami harbor."