Well, it's bound to be noted somewtime, and in all effect hiding something is close to lying. If he has such a dead set opinion that furries are bad, but you're a good friend of his, then you being a furry might just show him otherwise. I'd try to be as open as you can, and deliberately point out that you've found it hard to say because you thought he'd be negative. If he's truely a friend of yours, then that'll stay.