So, I suppose I need help speaking to my future-father-in-law.

I often post links and statements on Facebook supporting the LGBT community. My father-in-law sees this as an opportunity to turn it into a political debate each time. He usually also "demands" to speak about this topic in person.

Problem is, he is a terrible person to have a conversation with in person. He is a verbal bully, very intimidating, has a tenancy to belittle ones beliefs, questions everything one has to say, demands one produce sources, interrupts constantly, etc.

I have told him on multiple occasions I will not speak about these subjects in person, but I haven't been able to politely tell him why I refuse to have these debates in person.

Any ideas?