Meeting boyfriend's family???/fiancee

So my now fiancee and have been together for almost 5 years. And I have never met his family. Yes we do live in different states. But I don't think that's the issue. Every time I bring up the topic of going to see them he says yes than when the time is close he doesn't want to go. I feel like he may be a shame of me or his family. I say both because I'm black and his white, but I think he's ashamed of his family because they are well broken. His mother is a drug addict. And they're not even on speaking terms with each other. He only speak to his father. The rest of his siblings he doesn't even know their phone number. How do I get him to let me meet them. Without the pressure?