it is usually proper etiquette to use cutlery to bring food up to your mouth, and then chew with your mouth closed. especially at a fine banquet, anything less would be considered 'faux-pas'.
Faux Pas means literally translated 'False Step'
It is when someone make a 'Social mistake' such as doing something unaccepted or saying something wrong.
"Eric made a total Faux Pas last night when he bought a wine that the host of the dinner party didn't like'
Girl: Can I play the guitar next to Keith in church?
Boy (loudly so that every churchgoer in the congregattion can hear): So you fancy him them?
Now, my boy, that is a faux pas.
Translates directly to false step in French. Translates indirectly to embarrassing social fuck up, which usual makes everything awkward for everybody involved. Major party foul
Man did you see hunter try to make an unwanted move on that girl and get shut down? What a faux pas.