Easy tiger, that was just a joke. Its kind of hard to tell the tone with the printed word sometimes, but it didnt look like that was meant to be a rude response at all. Brezzy was right, it is a defense mechanism. They usually only spew it out when disturbed, so its a little weird that you are seeing it all the time. Its not a problem for your dragon, though I have seen some dragons have skin reactions to it on rare occasions.