Holy shiz, I need some major fricken help, ASAP!!!!!!!!!!!

so lemme get this straight 2 guys and one your with and another you want to be with. plus they both like you and they are good friends. okay question, do they know about your relationship with one another that you secretly like his best friend?
if no, i suggest just break it off. BOTH. i'm serious, as much as it will break your heart you are doing the right thing by walking away. they are good friends, you dont want to be the cause for their friendship to potentially fall apart. furthermore, you may not work out with either of them so break if off. sneaking around is never a good idea, considering they are close friends they will most likely fin out. and you might find yourself in a position where they both turn on you blaming you. trust me friendship alway comes first.
If yes, and he is a okay, still break it off and walk away. even if he says he's okay, he is not. no one ever is. dating someone's ex just creates tension. and is never a good thing.
i know this is probably not what you want to hear but this is my opinion. oh how i wish i was wrong and hope that someone has a better solution.
but to keep your friendship with them and for them to remain friends, its the only way. cause sooner or later your feeling for with one of them will surface and this cause bigger problem so my advice is to break it off.
hope i helped, good luck :D
also, i never expreience this before so my advice is based on fiends who have been through this and other information.

Stay with Shon.