Recently there have been a few articles published about opinions of boyfriends having girl best friends. Many people are divided on what they think about this situation, just like with basically any matter in life. I have to say that I agree more with Yes, I'm Friends With Your Boyfriend: Get Over It, but I am not entirely on this author's side. Like any situation, it depends on the circumstance. You can't control his friends, just as he can't control yours. If your boyfriend has a girl best friend and he flirts with her, you are wasting your time obviously.
My boyfriend and I are best friends, and that is how it should be. He has good girl friends and I have good guy friends, but since we respect and trust each other, we don't worry about this stuff. The person you're dating should be your favorite person in the world. If you and your partner aren't each other's favorite people, you haven't found the right person yet.
Hey If Your Boyfriend's Best Friend is a Girl author, this could be true, if your boyfriend is hanging out with his girl bestie more than you and can tell something fishy is going on. If this is the case, the boy is the problem, not the girl best friend. Perhaps you're looking for love in the wrong places. If you were truly in mutual love with your boyfriend, this wouldn't be a problem in the slightest. It would hurt if any of your best friends had a best friend other than you. Although, I have multiple close friends that I call my best friends. Just having one best friend is an elementary school idea.
Instead of telling him who he can't be friends with, find a better guy for you.
Girls who have guy best friends with girlfriends, don't tell his girlfriend to break up with him and find another guy. That is not your place to make any call. If he is your best friend, that means you respect him and want the best for him. Telling his girlfriend to break up with him would likely make him sad.
If you have any concerns about your boyfriend's intentions, chances are you're not meant to be. There are plenty of fish in the sea that aren't cheating douche bags.