Q&A How Do I Navigate Contact With an Innocent Friend, Who Was the Focus of My Husband's Sexual Fixation?

My husband has struggled with pornography and objectifying women, although he has now been porn-free for about six months. During that period, he developed a sexual fixation on one of my closest friends. There was no physical or emotional affair, and she has absolutely no idea. Because she visited our home frequently and was familiar and available in our lives, that objectifying pattern eventually attached itself to her. He looked at her photos and masturbated to them a few times while fantasizing about her for a couple of years during my pregnancy and postpartum. After it was revealed, his bubble was destroyed and he couldn't even understand why he felt that way about her. It was forbiddenness, availability, escape. She has been my close friend for over a decade and is like a younger sister to me. If she had participated in an affair, removing her would make sense. But she did nothing wrong and relies on me like an older sister. Distancing myself from her feels unfair, yet my brain now associates her with the most traumatic experience of my marriage, so I've been avoiding her. This has generalized to other female friends too. I'm hypervigilant when my husband is around them, making gatherings like our child's birthday stressful. Avoiding friends altogether would also be isolating. Intellectually, I know this was about my husband's patterns and choices, not her. Emotionally, I can't separate her from the trauma. How should I navigate contact with an innocent friend who was the focus of my husband's sexual fixation? Can this association be broken so I can eventually feel safe around her without cutting her out of my life?