Hey there Artchic! It's funny, I am in the same situation although I don't live with my parents anymore. I came out to them when I was in the early years of high school as bisexual and they simply brushed it off as a phase which was really disheartening to have your parents scoff at your valid feelings. So now I'm in a place where I feel like I have to come out again since I just separated from my boyfriend and want to be with women now, although my parents have said they support me in my life whatever I choose as long as I'm happy and healthy. It's still scary! I'm actually more worried about my brother judging me than my parents.
Anyway, since you're afraid they might kick you out and if you are planning on living with them for a while, you don't have to come out to them! If you want you can just wait till you move out if you feel compelled to come out to them or you can take a leap of faith. I know it can be really hard, especially for us bisexuals since people(even gay or lesbians) can scoff at us because we aren't "choosing a side". But people forget that sexuality is a whole beautiful spectrum! How cool is it that we are not just black and white? Just know you are not alone in your struggle and I support you in whatever you decide to do! Maybe if you plan on telling them, get a back-up place to stay just in case?
How did your dad react to same-sex married being legalized? If he didn't react badly, he may not react badly to you being bisexual. Or if you don't know how he reacted, ask him how he felt about it and go from there? Hope this helps! Also, therapists are always a great tool to help with conflicted minds...