Seriously, Shog, if your friend goes there, advise him not to bring his teenage students with him. Explain to him that furries are, quite simply, sexual deviants with a penchant for bestiality. Tell him about the furry orgies, about how people have sex in fursuits, how people believe they're actually animals trapped in human bodies, etc., etc. That should freak him out enough to make him back out.
That sonarrat guy who constantly argues on GAF about how furries aren't into bestiality recently admitted to trying to fuck a horse as his first sexual experience, apparently.