['Have you ever been in a situation where you had food on your face and you walked around for awhile without anyone telling you? This just happened to me yesterday and I was so embarrassed!']
Of  course I have, it's really hard
Just the other day, I was quite embarrassed at work. I was wrapping up my lunch and talking to a coworker. I must've been talking to her for about 5 minutes before she said I had food on my chin.