My parents don't say anything about me watching anime, but if they did, I really wouldn't care. I would just ignore them but they would easily show me how much they're a bunch of ignorant Americans, aswell as other people. Americans mistakingly compare Japanese Anime to the crap American developers make nowadays called cartoons, but that would be a complete failure of a comparison. Japanese Anime is really as various as the American Movies, which would be the elegible comparison. So, if you just show them an anime like Elfen Lied, then I bet you that they'd change their mind about anime being for children.
i just put on these huuuge headphones and weather or not some thin is on they think i cant hear em and i pretty much act like it ... rite now thier primary concern is to get me off music :S best of luck to them muahaha