According to the situation you are in, you would do better by asking yourself who would keep you happier - your present boyfriend, or the best friend you talked about. It is true that best friends for long times make the best lovers, but you should also consider your present boyfriend. He also has feelings for you. If you ever think that he is getting less interested in you, you should tell your best friend about the love you have for him. But be careful not to mess up into a love-triangle. Finally, the decision is yours. Hope I could help you.