The person who blows their nose in a restaurant while still sitting at the table, booth, or anywhere within hearing distance.
It can ruin my meal in an instant - no matter how great the food is, just the sound of SNOT shooting out and sounding like anything from a "TRUMPET" to a semi-clogged DRAIN, really ticks me off!
I cannot understand why people do this while others are eating within a few feet of of them.
I mean, I can handle a wipe or a small sniffle......but........ BLOW YOUR HORN IN THE RESTROOM!
How would they feel if I were to shove a napkin down the back end of my pants, take a deep breath and fart.....squirt.....squeek......and eventually pass a THUNDEROUS chunk of TURD, all while they eat their meal, then place the napkin in my pocket ......like nothing happened?