Everyone is different. I can only relay my own experience.
I married a man who, while raised Catholic, really considered himself to be agnostic. I figured it was no big deal. We got married in a Catholic ceremony. He agreed to raise the children Catholic.
However, in the end, the fact that we were so different in our faith led to the destruction of the marriage. I was extremely lonely in my faith. On only very rare occasions would he join me at Mass. Often, I walked alone, and thought about how much I wished to have a “partner” in my faith. I never imagined how difficult and lonely that would be… until I was in that situation. I raised the children alone in their faith. My husband would go to the important rites of initiation, but he never felt fully present. He was just going through the motions, and I knew it. I prayed regularly for his conversion, but evidently, his heart was just too hardened.
After the divorce, any of the very loose ties he had to Catholicism dropped away completely. When the children would ask him about God, he would promote his agnosticism. Since he had the right to see them on Christmas eve through Christmas day and continues to do so, my young adult children now haven’t been to Christmas Mass in decades.
Thankfully, I was able to get an annulment for this marriage. I later married a man who was a faithful Catholic and it was a joy to practice my faith with him. He has since passed away. My current boyfriend is also a practicing Catholic. I couldn’t have it any other way.
You are young… and so many men are yet to come. But when you are young, it’s hard to believe that. The one thing I think the two of you have going for each other is shared Christianity — and the fact that he asks questions and is very curious. Perhaps you have a potential convert! My own mother-in-law converted from Lutheranism to Catholicism to marry my father-in-law, and she was and is very faithful. Maybe that’s a conversation the two of you could have?
No matter what — I wish you both God’s blessings!