When you receive a blowjob. However, this isn't just any blowjob. This is when the person receiving is taking a large and vigorous shit. So vigorous that when the shit collides with the water the velocity of the steamy dump alone creates a glorious splash effect on the other persons face. If done correctly, then the person who is sucking the receiver's penis should be thoroughly soaked in shitty, smelly, and most of all sticky diarrhea. Extra points if you want to go all out and squirt diarrhea on the other persons face and mouth creating the Cambodian Mudslide and then dunk the persons head in the toilet and flush.
David: Oh shit son, I can't believe Bonquisha just sat their and took that Cambodian Fire Hydrant like that!
Malcolm: Hell yeah money, at the end she looked nastier than tubgirl.
David: I gotta give you props on that shit. On second thought don't shake my hand you sick fuck.(*dials 911*)