Spitting?

Jimmy's newest behavior... spitting. Solely at school. I have seen him drool and be fascinated by it, but the boy is seriously, defiantly spitting at school. I don't know how this started, but I am hoping it is a temporary behavior. It's not a pleasant or desirable one, especially in this age of concern about bodily fluid. If you think people flip out when you cough or sneeze now...