I'll refrain from offering advice because I waffle between hard and soft responses to the WW (I'm leaning toward harder today). But, what I will say is that the nebulous "friend" moniker is just to make you feel like it's an innocuous relationship. If it's negatively affecting your marriage, then it is not innocuous. Keep that in mind and don't let her talk you into the friend bull$hit; he ain't no friend of the marriage and neither is she right now.
