Why does my wedding turn into a brawl?
Solution 1:
You need to talk to your new spouse for a remarry and then talk to the priest for the remarry, but only once! Then the wedding will start.
Solution 2:
Ok, after trying on the same try about seven times, then getting derailed while my family took over the TV to watch a hockey game, I tried to do a Cold Feet retry and it worked. Now happily married.