Luckily my parents are really REALLY supportive of my cosplaying hobby. In fact my dad always suggests that he's going to cosplay Gluttony from Fullmetal Alchemist and I'm just like: Please. No.
But my parents are also very protective over me, despite being twenty one, when it comes to cosplay. I remember when I was 17 and I had my Sailor Mars costume XD
Me: *twirling around in it* Teehee. I feel so pretty :3
Me: And the skirt part is nice too, right? And--
Me: ......What? *blinks rapidly*
Dad: You are NOT wearing your normal underwear for the convention, missy.
Me: And why not?!
Dad: I will not have some guy being able to easily see your ass!