13 yr old bisexual *pls read*

Faye
Sooooooooo, I am a bisexual 13 year old that doesn't have the guts to tell her mom that she is bi. My friends know, and I even have a crush on one of them. She is also bi and we hold hands while walking through the hallway, give each other 5 minute hugs, and people even ask us if we are dating. We pretend like we are YouTubers Dan and Phil and we call eachother our husbands. Either way, I asked my mom on her opinion of the lbgt community and she said that she supports it! She told me that if I decide to become apart of the lbgt community that she is perfectly fine with it and would support me. Idk if I should tell her I'm bi or not because I'm scared she would tell either my dad or my step dad (both of which are homophobic). Can you guys give your opinions on the matter and help by giving me advise on what to do?