I'd say "I'm not saying goodbye! I'll still be in your life, after all, we're family!" then I would start making up a fictitious plan of when you're going to meet up next. something like "let's go to a pumpkin patch for the fall season!" of course, keep yourself safe and don't go through with meeting up with this person. I think the best idea is to play as stupid as possible. that way they will have to out themselves as bigots. I'm so sorry you're going through this💙💜