Who should I come out to first?

After many months of thinking, I have finally decided that I am indeed biual. The only problem: my parents are s. I think that they're afraid that I won't turn out straight (which I'm not). Like whenever a girl kisses a girl on TV. my mom screams out "Eeeew! That's so wrong!", yet she doesn't say anything when a guy and a guy kiss :/ My parents believe that ity is a sin, but I definitely do not agree with them. On the other hand, my best friend has never been rude to me and has accepted me for my differences ever since the start. The only thing is that if I tell her, she might think that I'm attracted to her (which I am). Also, I get the feeling that she might be / too, as she has never had a crush on a boy. But I don't want to ruin our friendship, so I'm really scared to tell her. So, who should I tell first: my phobic parents or my supportive yet weary bff?