Just out of curiousity, how much trouble would she have been in for slapping him? (IMHO, that's the only appropriate response to that kind of question. Except maybe if it was a doctor asking.)
If your answer is "a whole truckload of industrial-strength trouble," then we clearly have a sign that the schools' priorities are bass-ackwards.
I have a better one. Spit a big gob of spit right in his face, then say, "Hmm ... guess I spit ... do you swallow?"