Ok I'll just shoot from the hip.
How about.......babycakes or (insert kind name here), you know I am going to the RC with you this year, and you know that isn't easy for me. I don't want to fight, because I love you very much, but I also know there are a lot of very over the top things going to be said this year.
I wonder if it would be ok, AFTER the convention, for us to have an open and honest conversation about those things. Free of judgement, and flailing emotion. I promise to hold judgement and my temper/rants, if you promise we can have a real back and forth conversation.
I love you and i know we can do it, its so simple. we should be able to don't you think?
Anyways.......prob what I would do, but just thought I would throw it out there.