The boys at school love to spit everywhere, including inside the building. We demerit the heck out of them when they do and tell them that it is not at all acceptable.
Um...sometimes...read on.
Please don't hate me, but I spit. Asthmatic bronchitis has plagued me for most of my life, and I wake up with (turn your head, jdarg) globs of green stuff that gets coughed up out of my lungs. I don't want it in my body anymore, so it goes in the sink. Bleh.
If I'm not near the sink, it goes discreetly into a tissue. And (God help me) if I'm running, it goes into a bush when I think nobody's looking. My girlfriends taught me to be as discreet as possible (they sometimes do it, too) and we excuse ourselves (like when you sneeze or cough) when it has to happen.
It's icky, and it should never be done indoors or polite company, but spit happens.