Then, she must wait for the husband to become aware of his friend on this level, or not. For her, be aware of your own safety. Recognize clearly what the threat of this friend is. If it simply is that he spends more time with your husband than you, then invite your husband to get re-involved with the relationship. No one likes to hear someone simply complain.
People like to hear solutions.
Again, if this is a concern for personal safety. Make sure to not ever be alone with this person. Observe your husband's attitude and body language to see if he is still having a good time with his friend. If your husband becomes too much like this friend, make a decision for your self. Blessings to you.