Bilby, boundaries are so important. When he won't even discuss them, it means he has no respect for you. That is not cool, in my humble opinion. PTSD or not, that just isn't the type of person you want to be married to. You will end up with zero self-esteem, and allow things that might hurt you emotionally or even physically for years afterwards.
Many years ago, before I knew I had PTSD, I was married to a marine who had PTSD. When I first met him, he was a kind, caring, gentle man. He was good to me and my little girl. She loved him very much, and we were happy until something triggered him.
I had two rules in life back then. 1) No violence. 2) protect my virtue.
Then, his PTSD kicked in. He started to self medicate with alcohol. He was a mean drunk. He changed. When we would go to shoot pool, he would accuse me of flirting with the men there. I wasn't, but he imagined I was, so soon we stopped going. I had a lot of house plants, and he was even jealous of them. One day he ripped the big one in the living room to pieces. Then tossed the pot through the large plate glass window. One night, he came in while I was reading my bible. He grabbed it out of my hands and told me I loved it more than him. I got my daughter and left the house for a little while.
When I got back, the house was in shambles. He had tossed the furniture and ripped the stuffing out of some furniture. My large scissors were sticking into the wall and he was gone. I packed some clothes and we left again. I took us to the mountains so I could figure out what to do. Because of my daughter, we came back out of the mountains and went back home.
When we got back he had sobered up, and calmed down. He told me how sorry he was, and he'd not drink any more. I believed him. Life went along pretty good for a short while, then, one day a friend of his came over. My husband wasn't home, but the guy said he wanted to wait. So I left him in the living room watching some television and I went about finishing my chores. As I was putting away the laundry in my bedroom, this guy came in. He pushed me onto the bed, and tried to rape me. I managed to get away from him and ran into the living room. I got the baseball bat and told him if he came near me I'd bash his skull in. He laughed, but he left.
That night, when my husband got home, I told him what had happened. He accused me of enticing the guy to come into the bedroom. He said his friend had told him all about it. AT that point, I knew I couldn't stay. I no longer felt safe. If he wouldn't even protect me from his friends, and protect my virtue, I wanted nothing more to do with him. So I grabbed my daughter again and left.
Bilby, he might not want to hear it, but you need to tell him anyway what your breaking point is. Then, stand by it. Don't accept it if he breaks it. And he might just test you to see if you mean it. Please, for your own sake, stay safe.
Off my soap box now.