Regarding your question about a spouse having a close relationship with a best friend, it's not uncommon for people in committed relationships to have close friendships outside of their marriage. These friendships can be with people of any gender, and they can indeed be very close and meaningful.
Whether a close friendship between a spouse and their best friend is considered "too close" or not depends on the individual dynamics of the relationship, the boundaries set within the marriage, and the level of trust and communication between the spouses. Different couples have different comfort levels with their partner's friendships.
If a spouse has a close friendship that causes discomfort or concerns within the marriage, it's essential for the couple to communicate openly and honestly about their feelings and expectations. Discussing boundaries and feelings can help both partners understand each other's perspectives and work together to find a resolution that respects both the friendship and the marriage.
Ultimately, maintaining trust, mutual respect, and open communication are crucial in navigating friendships and relationships within a marriage. Every relationship is unique, and what might be acceptable in one relationship may not be the same in another. It's essential for couples to communicate openly and find solutions that work for both of them. If necessary, seeking the guidance of a marriage counselor can be beneficial in addressing any issues related to friendships or relationships within the marriage.