My roommate is an old friend of mine, former roommate from years ago. These two have been living alone for a few years, though, just the two of them together. The noise... snorting when it's hot, always open-mouthed eating, smacking, slurping, belches and coughs.... it's just foul. I leave the room at dinner time. I love these two dearly, but my gosh, it's ridiculous. They're wonderfully intelligent, but I don't know how to say 'please keep your mouth closed.' I think I probably should just keep my mouth shut (no pun intended), and just try to stay away during feeding trough time. Any advice? EDIT: the phlegmy clearing of the throat and spitting... c'mon guys....

tl;dr: need help in how to politely deal with housemates' table manners