If the parents don't get along, you may want to put a buffer row between the mother and the father. If the bride or groom has had a close relationship with former in-laws, it is not uncommon for them to be invited to the wedding. This is something that should be discussed with the new spouse. They would also be seated in honored seats with other relatives. One of the biggest mistakes a couple can make is trying to make divorced parents act as a couple that day.
Most adults can deal with it for a brief time and most people rise to the occasion.
Because divorced couples should not act as a couple, they should also be photographed separately. There are some parents who wouldn't object. Sometimes couples like having parents together in a photo together for the sake of the family tree. But as a general rule, you don't do that. It is best to talk carefully beforehand with the photographer.