Non-existent sex life/trauma.

Do sexual abuse survivors sometimes re-create their trauma? My wife and I got into a huge fight today. My wife's brother stayed with us for a few weeks and one morning, he got up way earlier than expected and came upstairs while my wife was making coffee. She was wearing shorts and a tank top because she wasn't expecting anyone to be awake. She was really upset by this. Fast forward to today. I came to the kitchen earlier than expected and the same thing happened except this time she essentially felt violated and likened the situation to being the same as it was with her brother. I was obviously offended since I am not her brother.

She later told me or should I say yelled at me, that she feels disgusting and humiliated about her body and that everyone just wants to spank/slap her huge, jigglely, ugly fat ass and that she can't believe I pushed her to humiliate herself. She's a size 4 by the way. She doesn't remember her sexual trauma but something clearly happened. My question is, clearly something did happen and it would seem that it has something to do with her butt, why are spanking videos her porn, her form of eroticism? We tried it once because I thought that it was her "fetish" and it didn't go well. She insisted that the spankings weren't supposed to end in sex. Is that because it was more of a "fatherly" spanking? I think it was the nail on the coffin of our sexlife. What if it was just a re-creation of her trauma and that's why our sex life essentially ended?

I suppose the idea of couples' therapy would not be met well?