Her message is highly manipulative but it doesn’t surprise me that you were the last to know. It sounds like her relationship with her husband is toxic whereby they “one-up” each other by keeping people who they’ve been romantically involved with/had sex with as “friends.” Whether people want to admit it to themselves or not, they either do that because they have unresolved feelings or because that person still serves them in an ego-driven way (or both).
I’m so sorry that you’ve been dragged into this utter toxicity. I don’t believe that they truly believed that you knew, by the way, at least not deep down, and I get the sense that they’ve kept you “out the loop” in multiple ways.
Everything about her response gave me the creeps, from her “matey-matey” reasoning of why she wouldn’t be with your husband, to her closing line of offering for one of you to stay at theirs. She clearly gets off on how entwined she is in your relationship and loves the ego boost, attention, feelings of validation and of significance that it gives her. That this man thought so highly of her he managed to “convince” his wife to keep her in his life.
This woman needs serious help and her husband is clearly along for the ride because she lets him get away with so much as well. What a mess. A mess your husband has dragged you into (I’m not going to comment on him specifically as I think others have said all that can be said).
Like I wrote in my first post, everything will be okay, OP. You 100% do not need this utter toxicity and gutter dysfunction in your life, nor do your girls.
I was in a relationship with a guy from the age of 21 to 28 (but we were on-and-off since I was 16), I also thought he was the most beautiful, wonderful thing to walk the planet (he’s an actor, so the toxicity was fuelled by him getting lots of attention) that ended in a similar way to you, but I let it drag out for 10 months longer than I should’ve and left the relationship physically emaciated and emotionally hollow.
I thought I’d never heal from the relationship ending, and honestly it took years, but those years of healing, blood, sweat and tears have seen me emerge with a successful writing business, a great relationship with God, a loving husband and a renewed energy for life, and an overhaul of my self-esteem - none of which I had in that relationship.
You can do this. Sending you so much love and hugs.