What happens next?

How to tell your siblings you are bisexual
Tell them in person if you can.
There are plenty of ways you can go about sharing the information you're hoping to convey to your siblings. Your relationship with them, as well as any potential qualms on their part will factor into this decision.

Available choices: A). However, your parents may not react well to the idea of this being a private matter. It's best to be in private and don't feel pressured to tell your parents about it and you might be able to find an alternate way to tell your siblings you are bisexual. B). They may be curious about it and use this information to decide how they can enable you to talk and share your secrets freely. Mention to your family about your sexuality, and provide all the details you are absolutely comfortable sharing. C). It may seem hard to bring up the conversation. You can ease into a more serious conversation by saying something like, " there's something important that i want to tell you because you mean a lot to me. D). As soon as possible after being told you are bisexual, give them lots of time to get ready. Make sure that they are in a safe environment with no one else near them.
C).