A sex act in which two individuals first engage in anal sex until the receiver's anus begins to bleed (This may be facilitated by witholding the use of lubricant or by performing intercourse on a person whose anus is unaccustomed to fornication).
Upon sight of blood, the receiver is placed in a "bottoms-up" or "piledriver" position (if not there already) and the other partner proceeds to defecate into his/her butt crack- thus placing the brown "meatballs" into the red "sauce" between the two "buns." Semen "cheese" may then be added to the sandwich by the "chef" if he chooses to self-stimulate himself to climax.
Mary: "Hey Claire, why the long face? And why are you sitting on a foam donut?"
Claire: "Jim got me drunk enough to agree to a meatball grinder last night. It's bad enough that I can barely sit down, but my sheets are ruined."