My family doesn't care at all, though I was raised in a home where expression, creativity, and most importantly, tolerance was always preached. Plus, I've always been the kinda guy to do my own thing and not give a flying feather what others think. So for them to find out I dig a show about pastel colored, cartoon ponies is no big shock, haha.
My family is two sister, older and younger, who are both Pegasisters, and my mom and dad. My dad doesn't know. We aren't close, and we fight a ton. He would silently jude me, and that would suck. My mom would also judge me, so my parents don't know. (My sisters both know).
My mom's perfectly fine with it, my dad not so much. He just rolls his eyes, makes fun of it, then I remind him of the animes and shows he likes, then he just shuts up about it. My mom, she secretly despises it. This is how it went down: Dad: What're you watching? Me: NOTHING. Dad: No, show me. Me: MLP. Dad: Pft. Okay thennn... Yep.
I've never felt the urge to openly announce all the things I'm a fan of, but since I also make no effort to hide them, they probably know or at least suspect. My mom is usually passively supportive about this kind of stuff, showing no interest in it herself but saying: "Well, as long as it makes him happy, I don't mind." With my father, it's a bit harder to tell. If he knows, he most likely despises it, but he dislikes pretty much everything I do and has by now chosen to ignore most of it, preferring to pretend that my hobbies don't exist, so he may as well be willing himself to not be aware of it.
My folks are pretty cool with it. I'm still technically a child where I live, (until March...) so it's not as "weird" as in some cases... I'm also not an annoying loon about what I fancy, so there's that EDIT: It's been so long that I forgot that I already wrote in this topic. Ehehe...
I've not really said anything about it, I usually watch the episodes on my computer upstairs. Though I think they may have some idea of it, example being during Christmas shopping we passed by a set of toys and dad just yells out, "Hey! Is that purple one Pinkie Pie?!" What? No, that's Twilight Sparkle. Comon man, it's Pinkie Pie, it even says pink in her name. Mom & Dad: >.> <.< What's with the weird looks?