When a guy puts his cock through adoughnut(usually a suger glazed) and then proceeds to either get a BJ, fuck the pussy or ass. It's helpful for those with really big cocks to add extra cushioning. Sometimes after the fuck, if the doughnut isn't destroyed, then someone can eat it.
Last night my girlfriend said if I wanted to fuck her ass then she needed a Doughnut fuck cause my cock is too big. After the workout she needed a suger boost so she finished off the doughnut.