This is a dream that reflects her ex-husband's incompetence, weakness, disgust and resentment.
Maybe you always feel that marriage is stressful subconsciously. Maybe your ex-husband is excellent, maybe you have always looked down on your charm, so you have always had a sense of crisis, and you have always had a faint pressure and worry. Dreams are just distorted reflections of reality in our minds. It doesn't matter what the dream reflects. What's important is that we can better understand our hearts and improve our psychological situation through dreams.
Dreaming that your husband is sleeping in someone else's bed and having such a dream essentially shows that your love for your husband is not as good as his love for you.