N.S.
Oh boy. I think you need to decide with your husband what you think is the best thing to do. I hope your husband will understand that your dad was mainly acting out when he said what he did. If your husband is going to get very hurt just by hearing the story, well, you already have your answer.
I say this because you cannot protect your husband from your dad's drinking. (Of course, you can protect your kids from it, that's different).
It seems like your dad likes to hurt others when he is hurting. You need to set boundaries revolving around that. Your dad should learn that some behavior is unacceptable to you and your family. It doesn't matter if he is drunk when he says or does inappropriate things. He still should have to deal with consequences.
Also, if you feel you cant handle getting into details there is nothing wrong with telling your dad that you have to bow out of dinner and you are sorry ( no other explanation). At least then you will have protected the sanity of your immediate family. You will probably have other chances to deal with the issue of your dad's acting out and can give yourself some time to prepare how to handle them.
Sorry you have to deal with this. it is a tough situation.
Oh and in reference to your "what happened" comment. That is a classic situation, the alcoholic taking focus off himself and his poor behavior and putting it on someone else. It doesn't matter if what he says has a grain of truth, what matters is how you handle your boundaries. Did he cross a line? You need to draw the line. Do you need to talk to your husband about discipline and the kids? That is a separate issue. I think you might benefit from Alanon meetings or literature. Best wishes.