In front of parents? Hmm... 'coprophaegic' I suppose (from copros= s**t, phaegeia= desire to eat. Pretty sickening...) Not to be confused with 'coprolallic' which means 'desire to speak s**t' - in other words, one who uses particularly dirty language!
In studying ancient Greek, I was most amused to find that the greeting addressed to one person is 'Chaire' (pronounced KHIYE-ray) - because in Arabic, that's quite a foul obscenity!