You might not see it now, but your agenda of getting married could easily damage this relationship. By focusing only on your future how can you enjoy the spontaniety and growing love that a new relationship can bring? Don't you trust him? Finally do you love him as well? Then just go with it and accept your relationship as it stands for now. It's too soon to know if he is marriage material.
We are what we think. All that we are arises with our thoughts. With our thoughts, we make our world.
“When I let go of what I am, I become what I might be.” – Lao Tzu