This is when two men have anal loving and man number one ejaculates into man number two's ass crack, which coincidentally is filled with small pieces of fecal matter that have become entangled in the hair found in and around the area. Afterwards, man number one mashes his face in the crack and attempts to eat as much of the fluid while it's still warm.
"Oh, I'm about to bust a fat nut! I'm going cum so hard, this'll be the largest hot dingleberry milkshake I've ever had. Now suck that cock, fag."