As a man I can understand your husbands POV. Maybe you should try looking at it from his perspective. How would you feel if his BFF was a woman? Is your behavior with your male friend appropriate? are you sharing things with him that you wouldnt with your husband? You say that he was okay with the relationship before marriage so what changed? I wouldnt give up on your marriage so quickly and over something that is easily fixed. I think its sad that so many people just throw away spouses and marriage without doing the work necessary to make it better.