If you've only been with him for a year or so I wouldn't mention marriage to him too much, plenty of people are together for a lot longer than that without marriage.
It's a funny one, I know you want some commitment for you and your son, BUT at the same time, that's a lot for a bloke to think about, men are really bad at talking about this kind of stuff.
If he's recently stood up in church and given an oath of commitment to your son, I'd take that as a good sign for now and relax a bit, he obviously feels commited, even though he might not talk about it much.