How to come out to same-sex best friend without ruining friendship.

Hello,I am 24 years old and still in the closet. I am bisexual, I'm equally attracted to men as much as I am to women. It took me a long, loong time to come to terms with it myself, and when I finally did, I felt a great weight come off my shoulders, but that weight has returned, as it's a secret I've been keeping for 3ish years and it's really starting to bear down on me heavily.I'm not overly social and don't have many close friends. I know coming out will ruin my relationships with some overly religious family members and I'm ready for that. I think I'm fine telling my parents, let's face it, my lackluster love life already has them suspecting something, and they have been even before I came to terms with it myself. I think they would accept it rather quickly. There is a one person I'm terrified of telling though, one of the singularly most important people of my life, my same sex, straight, best friend. He came into my life 2.5 years ago, and I feel has saved me in many ways. Like I said I am a loner and if it wasn't for him, after graduating college I would have been 100% alone. He's kept me company and been there for me through thick and thin, and I owe him so much. He knows I love him (as a friend) and I've told him that on many occasions. Now what I'm worried about is that I'll end up freaking him out and making him think I'm attracted to him by coming out.As many straight male friends do, we joke around a lot about inappropriate stuff. We joke about our genitals, and to the outside eyes we might even seem gay sometimes the way we act around each other. He says he's straight, and has shown support for the LGBT community in some conversations, but more along the lines of "If they don't bother me I don't care what they do". I feel that if I come out to him he might revert and think of all our normal jokes as me flirting, or being attracted to him and it terrifies to me to lose him, or for him to distance himself from me.My one wish is to tell him and for it all to remain the same. I want to have this weight that is crushing me right now off my shoulders, but I also want to keep the relationship I've spend so long building and treasure so much the same.Please any advice you guys can give me will be extremely helpful. I know he's my best friend and he should and probably would support me no matter what, but I'm still terrified.Thank you in advance and sorry for the ramble.