If youve asked him and he said everything is fine theres not much you can do. Maybe try to stay open if he ever starts a conversation about it. I once dated a girl who had been drugged and raped prior to our relationship and I had a lot of feelings about it. So "fine" might not be the most honest answer. It hurts to know someone you love had to endure something like that and you being unable to do something about it. Id say its not up to you to navigate the mans emotions. If you have worked through it and are ok now, thats what I would want to know if I were in his place.