How can I tell my parents I'm bi?

I tried to put this in 'Gay Lesbian and Bisexual' but the categories under 'Family and Relationships' wouldn't show up. Sorry for that.

I found out I was bi only about a month ago because I like my best friend and we might start dating, but a bit before that I was watching TV with my mum and sister and it was some kind of current affairs program and the episode was about gay rights and marriage and stuff like that.
Even though I didn't know I was bi at the time, I was still fine with gay people and I said I was completely fine with it and my mum said something like, 'It's ok with me, but as long as you're not; keep it out of the house.' I think she only said she was 'ok' because I said I was fine with it. I have no idea what my dad thinks.
My friend can't tell her parents either.
I have no idea what to do because I'll probably have to tell them some time or they'll probably find out somehow anyway.
My friend said she sort of wants someone at school to find out then put in on facebook so her sister finds out and tells her parents - so she doesn't have to tell them herself, but that probably wouldn't work for me. It's not that I don't want to tell them, it's that I don't think they'd accept it.
What can I do?

This isn't an ideal answer, but this isn't an ideal world...

Until you can provide food, clothing, shelter, etc for yourself, you are dependent on your parents to do so. Above all else, you need to make sure you're safe and fed. If you think your parents can't deal, then unfortunately that might mean that you have to be quiet about this until you're safely out of your parents house... like away at college. Sorry, I don't like this answer...