I started going out with my best friends 4 years ago. Still with her now infact. I have my regrets and I don't. Because it ruined our friendship but started something new and now if we break up, that will be everything gone whereas if we stayed friends we still could be, but I doubt it after 3 years. Best friendship with a girl always = going out or a date tbh lol. I would have been jealous being her best friend and her getting a different boyfriend. Would then mean I would be second best haha. But I love her to pieces now so I can't regret something that made me so happy :-)