i might like my bestfriend

I like a guy that used to like like my bff(fem. She didn't like him and i was the 3rd wheel. Hes been closer to me ever since he confessed to my bff. Thats when I got confused and I started to think that I probably liked him.

Now, I know that I like him but idk whether I have to tell my bff, because idk how she's going to react. Plus, I'm scared that if I tell him, he's not going to say anything at all and then go and tell his friends that I confessed.

I'm afraid that if I tell it either of them, they will get mad and it could ruin our friendship.

Can somebody give me at least one tip on how should I tell them? I think I should wait a while to see if I really like him, but it'd really help.