I think you are worried about your ptsd rubbing off and giving it to him. It can't. Plain and simple. No one, unless they've been there, will feel the intensity we feel.
I'm kind of curious why he wants to know every little morbid detail. That I would not give.
But what bothers you now, after the fact, should be avoided sexually.
I hate to have the back of my head pushed, I have an automatic reaction in my arms and hands on that one. So I tell people. Even childern, I tell them first off, do not touch the back of my head.
Have you tried emdr, eye movement desensitization and reprocessing.
It is a good treatment for reoccurring flashbacks. I don't have reoccurring, and have gone through it, but for me, because of the years of trauma I experienced on a daily basis, is more harmful then good.
I have never been asked the full on details. Well, I am very intimidating, so I guess that squashed those questions.
He does not need to know the full details, just the overall picture of what you went through, and what it has changed in you.
I can only give suggestions, but have you ever thought of couples counselling?
The only problem with that is the finding of a good counselor. He/she would have to understand fully about the trauma you endured, or its all for naught, nothing.
With me, I can turn myself off, well I am off, it's hard to turn on, but can you do that? Turn off. If so, maybe going to a safe place outside of the house like a park where you can be alone, you can "turn off", ask him not to speak, and explain to him as if you were a third person of what happened and how it has changed your behaviors. Still being turned off, go do something that is more like a reward for the two of you, something safe and stimulating, like going for an ice cream cone, and go to a totally different subject.
Maybe trying this type of speak, reward, and move on may help.
The reason I say not to have him speak, is that you may not continue to be able to keep "off", and it's your feelings that need to be given freedom and detachment from the event.
Sometimes when others want to help, they bring us to the places we always try to avoid. Anyway just a suggestion and hope you understand what I mean.
On other occasions, give him the time and place to speak, and listen to him in a turned off, (that's if you can) mode. Hear him in the third person, not letting your feelings get involved. Then again go do something positive in a positive scenery.
Maybe this can get you over the hump of the trauma, instead of staying on the top of it, reliving way too many times then necessary.
Still, I am curious as to why he wants to know the details...
I once had a boyfriend, (mine was sexual abuse starting at three and lasting way too long,,,), he asked me, as we were getting into an intimate situation,
didn't I ever enjoy any of it?
Well needless to say, mouth open in a huge gap, I slowly, cause that was a shocking question, got my stuff together, and mouth still open, looked at him as if I never met him before, and left, never to return or even think of him again.
So you are right, some information is top secret, and should remain just that.