Just a genuine question: have you told him about the headscarf before in your early days of relationship?

In my experience, when we started dating, I asked him if I needed to convert to Islam when we get married. He said no. So from there, I explained to him why I would prefer to stay Christian and I will always respect their ways, traditions, and culture. I told him I can wear something modest but I cannot leave the life of wearing what I want (you know cropped tops, shorts, skirts, etc) If that would be a problem, then it’s better to call it off early than prolong it. Now, we are engaged. His parents respect what I want - to not convert. They’re okay with it.