honestly? I say let them find out on their own. telling them yourself makes it seem like you guilty about it or something. like you're coming out of the closet. just continue with your life and if they ask, tell them it's a good show, and it's become very popular.
I just received Pokémon Y so I don't have any Pokémon with me yet :P well its something I do every time I get a newer Pokémon game, the older one gets archived and only used again if really needed, so do you really need it?