How do I casually date, and keep them from trying to have sex with me without being exclusive? I want to get married!

I recently just got hurt by a guy who wanted to take it "slow". We've been on over 10 dates, I gave in to sex. Now we are taking a break because he feels I was getting too attached. In a couple weeks he says we can hang out again to temper things. He says he doesn't usually rush into relationships.

Ladies, please explain causally dating to me!