Sexuality

How do you tell your mom that you bisexual? More like your maybe bisexual....do you have to tell her at all? Don't get me started on my dad...he homophobic I dont think my mom or my mother's parents care but my other side of my family is very old school. My brother came out to my dad and he called him a fag. I feel so bad and I don't wanna be next! If I tell my Mom she's gonna try to get me to tell my dad which is a big problem. I need advice ASAP.HELP ME!!!!