Coffee shop racism

Had coffee with Dad and two of our family friends earlier. All was well, then politics came up, and it came out that they believe Trump's tweets are the truth and Fox News is trustworthy. Ok, you can be blind if you like, go ahead. Then one of them (not my Dad but one of the couple) referred to President Obama at "the black devil" (in the context of 'that's what they call him down there' but without any clarification that they didn't share this opinion) - I was absolutely shocked, and ended the conversation. How can I ever speak to them again?

I should point out they have spoken about their trump-leanings before, I find myself incredulous every time but shrug it off. He even said at one point today 'well we'll just have to agree to disagree' after I questioned him on his belief that Fox News is the most trustworthy. It was at this point that, seemingly out of the blue, the "black devil" comment was made. I have never heard either of them say anything out right racist before, and at first I was at a loss for words, and asked him to repeat it, which he did and his wife backed him up on it.

It was at this point that I stood up, and said "this conversation is over," gathered my things and left. Dad got up and followed me, and we went back to the car. Honestly, these people are friends of his and have been for quite some time, so I would have been fine if he had wanted to stay there, I would have just walked home (it's not all that far away anyway), but he left with me. Later at home he told me that he had never heard either of them say anything racist before either.

About an hour and a half after this, let's call it a confrontation, we were at home playing a game when I started to feel hivey - anyone who knows me well knows that heat and humidity can set this off, but I wasn't feeling any of that. I had to take two antihistamines and a large glass of ice water and hold an ice pack on myself for a half hour before the reaction started to go away, and it wasn't until that point that I realized exactly how stressed out the confrontation had made me - stress and anxiety can also bring out hives, and this certainly could have been the cause.

Anyway, in discussing it with my Dad, and him saying he had never heard them talking in a racist manner before, now has me wondering if the instigator was maybe only saying these things to rile me up, because he could see how aggravated I was getting over his political leanings, and I have noticed a lot of men of a certain age like to just stir shit up (my grandmother was the same). Is it possible this was just to him a joke? In any case, right now I am unsure as to how comfortable I will be meeting them for coffee on my next visit home.

As weird as it is, I find myself hoping that it was a joke on his part, I wouldn't want my Dad's social connections to be strained in any way.