I Liked Her Since I Was A Child, But Over The Years She Became Love

So that's the job. There is a girl we have known for a long time and I love her very much. I liked her since I was a child, but over the years she became love, but now she is with a boy I know. But at the same time it is obvious that she likes to be with me, we flirt, sleep together, kiss and still she goes with the other boy who washes a friend :(. And what to do it is obvious that she loves me but continues to be with the other one where I freak out when I see them together.Whether she's afraid to break up with him because then our friends will talk about us or just watch me, although I doubt if she spun me it would hardly be for 5 years, I'm right I'm so simple. So give advice, share, or comment. I don't know how to make her break up with him, because I can't do without her, and she's with him all day. I've never hurt her, I've always been nice to her, I've always helped her, I bet I know more about her personal life than her boyfriend. And yet I don't know how to get her on my side. Maybe I'll tell her how I feel about her, even though she knows very well, I've told her more than once. I miss her all day, especially when we are at school, she is in the reverse shift and nz ... give me a little shoulder.