the act of performing veracious anal thrustage while the anal cavity has reached maximum fecal capacity. After fertilizing the know tender "potato" with your seed, place a dinner saucer beneath the anus. Watch the steaming spud plop onto the saucer with with copious amounts of your freshly churned genetic sour cream.
See also 'gravy boat'
Anytime Johny wants a loaded baked potato, I bend over and tell him "Fill 'er up!"