It’s better if you open up to him about marriage, especially if that’s what you also want. That way, you can find out what his real plans are or if he even has plans at all.
After five years together, you’re probably already very comfortable with each other, so there’s nothing wrong with bringing up the topic of marriage. It’s important to be open with one another.
It’s hard when you’re already thinking about something like this but you don’t say it out loud—sometimes that leads to bigger problems later on. It would be a waste of the relationship you’ve built as a couple.