I usually have a repulsed/slightly horrified look on my face whenever that happens. I can't help it, I express my emotions with facial ex<x>pressions -.-
I always wipe it off right away, and with a semi-disgusted look too
You could.........and make a scene lol.
If I'm in a bad mood I just spit back in their face!
Can't you? You should spit back. A nasty green one. With red stripes.
Or a serious night of heavy drinking and smoking if your already very stressed. :)