I know a big secret about my bestfriends boyfriend?

[A thousand years]

This is what I feel and of course this is only my opinion, as Im sure you could ask ten different people and someone is going to tell you something different. Anyways, I think you should tell her. I think as her friend that looks out for her best interest you have every right to tell her. I would want my best friend to tell me anything that could possibly hurt me. There are some things left better unsaid, as I know a lot of things about a lot of people, things I never thought were possible for people I know that are in the careers they are in. For instance, you look up to certain people and then you find out they are into something not so good and you cant say anything because you could ruin their life and I would never ruin anyone's life. BUT, if I knew my best friend was getting cheated on, I would say something because no one deserves that.