Are there any married couples where one is Catholic and the other is Christian?

It shou8ld not matter. Christians are nothing more than Catholics. Both originated from Constantine's use of the Holy Roman Empire / Roman Catholic Church to bring all of his empire under one religion to better control people. We are seeing the same happening today except it is under the name of Global Government and there is a lot of misinformation / lies being put out to control people just as the Roman Catholic church did. Our new lies are racism, inflation, global warming, COVID and other things to scare people into submission.