I have a friend who is in a similar place, except he is married. To me it sounds like the understandings you've come to are a good start. Some couples have a very difficult time even reaching the point you're at.
I would continue onward based on what you discussed, and keep planting seeds. You don't have to be pushy or anything, just continue to witness. If your parish offers classes as part of the catechumenate, perhaps you could invite him along—not in a "I want you to convert with me" way, but just so he can understand the faith you are coming into.
Most of all, pray for him. St Monica, the mother of St Augustine, prayed fervently for her son for 20 years before he finally became a Christian. She may be a help for you in prayer as well. Prayer has much more power than reasoning and debate, after all!