I'm pretty open about it.
I don't try to shove it down peoples throat, but i also don't deny it. Though, it's a bit difficult to explain it to people sometimes. You should have seen the look on my mothers face when I tried to explain it to her. PRICELESS!
All my friends know I'm a brony and they take it quite well. They tease me sometimes of cause, but not very seriously. (I think it's because they already thought I was a little weird, and this is just a new addition to my craziness )
All in all, it went pretty well for me