Family conflict with boyfriend

So me and my boyfriend started dating when I was 17 and he was 22 when we became close at work. It's been 2 and a half years since then and my family still refuses to meet him and he's begining to get mad at me for it and now he's basically threatening our relationship if I don't bring him to this event my dad's hosting. He thinks I'm not taking him seriously enough to try but I just know my family and they genuinely frighten me too much to try to bring him. What should I do?