When someone takes a dump, preferably incredibly sloppy, into a funnel (a funnel similar to the funnel used for chugging alcohol). While the partner chugs the whole thing up in one big gulp.
Dan: Hey Peter. Wright would you bring that luscious booty over this way, i feel like a 'mudfall funnel'.
Peter: Sure thing Daniel. Aston open up your mouth wide. I've been eating chili.
Dan: And don't worry, i'll clean up afterwards with my mouth.