Serious talk

I need to have a serious conversation with my boyfriend. About our future. We never talked about marriage, I'm not sure where he stands on it. (he has already gone through divorce) I know he wants kids, and so do I, but I'd rather be married first. For some reason I'm very nervous about this. I love him, and I'm afraid the answers he gives me might not be what I want.  The other day he said to me "I'm a good person, I'm also a horrible person" I'm afraid to ask him what that means. He has never hurt me in any way, but I feel like he might hurt me emotionally when we have this discussion.