When a man wears pants that are too tight and the seam of those pants where the two legs meet in the middle split your balls leaving one ball on either side, leaving the seam in the middle of the ball taco. Not unlike a male camel toe.
The least desireable form of a blumpkin (as if any are particularly desireable) for the giver --- That which takes place after an especially large amount of Taco Bell has been consumed by the blumpkin-receiver
During a particularlyrancid TacoBellumpkin, she received a splash of partially-digested Chalupa right in the face.