The sexual act of ejaculating into your partner's navel and then proceeding to slap the area on or around the belly (preferably the lower abdomen a.k.a. FUPA) creating a ripple effect that forces the ejaculate to spray from the navel. Many pride themselves on their Krakatoa giving ability. The ensuing explosion is often compared to a volcanic eruption, hence the slang Krakatoa.
Gomez was overjoyed to see that the spurt from the Krakatoa was enough to drench the city of Pompeii.
by Dax Nottinghood January 05, 2010