Growing up I was always taught you don’t stick your fingers in your mouth and pick at your teeth. It didn’t matter if there was something bugging you or food was stuck.
I was always taught after you ate and if you had something in your teeth you excused yourself, went to the restroom and picked at your teeth or some place private. It is very rude to sit there and shove your fingers in your mouth!!
Not only is it rude, it is very unsanitary. First off you just picked at your teeth, where a ton of germs live, then you put whatever it is back in your mouth. On top of that you then just and touch other stuff and your face. No it’s not okay that you just wiped it all over a napkin, WASH YOUR HANDS. You just hand your hands in your mouth!!
Since I’ve moved to Utah just about everyone I have meet does this. Sitting at restaurants, walking thru grocery stores, sitting at work, etc. To me it is just as bad as picking your nose in front of people. Your mouth is a dirty place, don’t put your fingers in it and then touch a bunch of other stuff, especially other peoples things.
But then again I forget where I am, the state where manners were never taught to children & they allow children to run wild.