I realized that I'm bi, and now have a girlfriend, but don't know how to come out to friends?!?

I'm sorry to say this, but it IS illegal for your lover to do anything with you until you turn 18. Now, if ANYone else hears about what you two do and feels like it, they can turn her in to the cops for screwing with a minor. It doesn't matter how strongly you stand up for her, it's still illegal.