Is your female friend’s boyfriend a douche? she doesn’t see it? you secretly want out of the friend zone?
Well if these are your problems here are two ways you can tell your friend that her boyfriend is a douche:

First you start a serious conversation with your female friend to set the mood, make sure she doesn’t think that you are joking. okay, now compliment her on her qualities and let her feel that you are there for her, not just trying to break them up. No simply say “You’re too good for him” and just compare her qualities and tell her she deserves someone equally genuine.

If that trick fails, you can always try the “You’re not the same when he’s around” let her know that she behaves differently every time he is around and just not being natural. They should not be together if she has to act like someone else for his pleasures.