Well, my Dad knows. He once caught me drawing ponies... It turned out he found my pony drawings earlier, and he said he wanted to see the process of creation... My Mom once saw a Luna wallpaper on my phone and said I'm devolving with this unicorn stuff... should have tried to explain her the concept of an alicorn with that attitude? :)

Mom: What are you doing? (over the phone)
Me: Watching TV.
Mom: What show?
Me:...My Little Pony.
Mom: .... okay?
Later, when she got home, it was still on, and she goes, "Wait - you were serious?"
It was pretty funny XD

Yep,they knew from the very start! we always watch it on the computer with my cousins next door..in the living room where our moms often watch T.V and gather..they dont really mind actually,they actually LIKED it! :D

My mom found out after we went through the drive-thru at McDonald's. It was when they had MLP toys for girls. My mom was getting a happy meal and they asked her for a boy or girl toy. I told her a girl toy and she was surprised, but she accepted my decision.