Well you may think that, but they might actually be accepting. Everyone tends to think their friends will abandon them and everything, but that might not be the case. People usually change their attitude once the issue of homosexuality hits closer to home. And if they do leave you, don't fret. They're jackasses for that. You'll find new friends.
Oh and sweetie, you're not 'turning' bi. Your sexual orientation doesn't really change. You may just be realizing at this point that you are bi.
well you onlythink your turning bi. wait and see if its any different and tell them. they might not b homophbes, besides it doesnt matter what they think. if you are bi you are, them not liking it is nothing to do with your feelings. its not like you can help being gay, bi, straight. or at least i don think