Preserving relationships after a divorce sounds like an oxymoron. You are trying to get away from the person, so why would you want to preserve the relationship? If you have children together, you will need to interact with each other for the rest of your lives. Co-parenting is a full-time job until children reach the age of majority. Life will be easier for you if you both if you can learn to be together in the same room without ugliness.
Studies show that it is good for the children if both parents show up for their events, like their sports, band, orchestra, or other special events. There will be graduations, weddings, and possibly the birth of grandchildren. It will always be in the best interest of the children, even when they are adults, if you and your ex-spouse can both attend these events and show solidarity and be cordial for the sake of children and grandchildren.
You do not have to sit beside each other to show solidarity but sitting in the same row shows the children that the two of you are a parenting team. You are still their mom and dad, and you are presenting yourselves as “team mom and dad.”
Some ways a positive post-divorce relationship is facilitated are as follows:
Traditional litigation is an adversarial process. Litigation pits you and your spouse against each other in a way that is designed to have winners and losers. Settling out of court focuses on fairness and facilitates corroboration that will carry forward into co-parenting in a healthy way. You are each guided to decision-making that benefits, as much as possible, both spouses.
When you settle out of court, it is much easier to be cordial and leave the marriage with minimal damage to the relationship. You can learn how to co-exist as part of the new family structure.