Most break-ups are painful. Not only for those who divorce, or their children, but also for family and friends. How do you prevent getting caught in the middle, and be a friend to both without ending up the bad guy yourself?
It’s best to develop certain “rules” for yourself -
Never choose sides. Be honest with your friends about this. Let them know that you value both their friendships, that you will continue being a friend, and will do your best to stay neutral (To be their Switzerland). Try to offer both freedom to vent feelings but do not get drawn into declarations of loyalty one way or the other (It’s a different scenario if there’s a clearly wrong party, however, e.g. abuse). Remember, this is their issue, not yours, and you're only trying to be a friend. (If you find your friendship isn’t helping, or that you're getting caught in the crossfire between them all the time, get out. Don't let their problems turn into your problems.)
Don’t judge. Unless you have the facts, never reveal your own opinion on who is right or wrong. He said/she said is seldom accurate, people always perceive the same incidents in completely different ways. Perceptions differ. Simply listen, be a sounding board, and "reflect" each friend’s feelings back to them. You don’t accidentally want to confirm the “wrong” believes or ideas.
Don’t’ diminish either friend’s pain. Even in an amicable divorce, both your friends are hurting. Both grieve for the loss of dreams, hopes, lifestyle, a lost future they originally planned together, and obviously, stress about the children. Once again, simply listen and offer them the opportunity to air their grievances or hurt. This involves silence when you may not want to be silent. This involves keeping the information you hear confidential even when you are asked by someone what the person said. This involves paying attention even when you may have heard the same story more than once.
Don’t act as a go-between. In international relations, this concept is called "shuttle diplomacy," where a mediator goes back and forth between two parties working on some kind of reconciliation (or to start world war 3). Such is not your job. Don't agree to carry any messages or "tell them something" when you next see the other party.
Keep your own agenda out of it. Even if you think the divorce is for stupid reasons, too bad (And if you want to introduce either one to your brother or sister -Don’t). It’s not your decision, and it’s not your life. Respect their choices and opinions, simply try to ensure their decisions make them happy.
Don’t trash the Ex. Expect anything you say to one to get back to the other. In his or her frustrations, one of them might use your “Hmms” or “Aahs” as validation of feelings or actions to prove some point to the previous partner, and eventually, you will suddenly find yourself of betraying secrets (in some cases, even being accused of trying to keep them apart).
Don’t gossip. You don’t want to keep the dramas going. It’s not necessary to share when a new girl-or boyfriend is introduced or that s/he was caught in a traffic accident, or anything else (sometimes an option is to simply ask which information can or should be shared).
Don’t compare new partners. Resist attempts by either friend to compare a new boy-or girlfriend to the Ex, whether they be smarter (or less smart), more sophisticated, the same haircut or anything. That EX is also your friend and requires your respect, as well as their previous relationship. Only when either one of them gets involved with a clearly wrong partner (e.g. a pathological criminal, serious personality traits) you can gently share your concerns.
Assist with the children (if this is acceptable to your friends). Consider taking them to the movies or other fun activities, collecting them from school, and so forth. It's a difficult and bewildering time for them as well. Just be careful not to take over their parents’ roles e.g. becoming the only one who disciplines them, or paying more attention to them than their own parents. And do not overcompensate for their losses by spoiling them too much or buying expensive gifts! (You will find yourself being manipulated in the long run. Children can be very clever to manipulate any situation to their advantage, and to play off adults against each other).
Neither is it your job to explain the divorce to the children. You may answer innocent and factual questions, though, but remember that the parents should explain the why’s and how’s to them.
Don't involve yourself to the exclusion of your own life because you feel so obligated to help your poor friends that you neglect your own relations.
If all else fails, detach from both until the dust settles. This is a last resort, to be taken only if you find yourself being “swallowed whole” by the situation. Tell them both very gently that you love and value the friendship with both of them, but find yourself too much in the middle of things for your comfort or to be of help to either of them. While you want to remain friends with both of them that you want to be sure you do not intrude upon their private hell or to worsen matters. Let them know that you want to give them the time and space they need to work out their issues without your interference.
Help them to reach out for help if they need it. If you notice your friend/s start showing symptoms of depression or experience unusual stress or anxieties, or when the children start acting out, consider helping them to find a professional person to assist them.
Finally, also remember that just because you were "friends first" with one friend doesn't mean you are contracted by the friendship code to be on their particular side in a break-up.
You are allowed to make your own decisions about whether you want to maintain a friendship with the other friend, or, to break up with the first friend as well. In particular if one has behaved so badly in the breakup (even when given chances to explain themselves, and the full benefit of your friendship) that you really don't want to be friends with them anymore, you have the right to “divorce” that friend, too.
Divorce is never easy! Neither is playing Switzerland. Best of luck to both yourself and your friends.
References
Chen, Stephanie. (June 10, 2010). Could you be ‘infected’ by friend’s divorce? Retrieved from http://www.cnn.com/2010/LIVING/06/10/divorce.contagious.gore/
Deal, Katherine H., and Grief, Geoffrey. (August 31, 2012). The impact of divorce on friendships with couples and individuals. Journal of Divorce and Remarriage. Vol 53, Issue 6. DOI: 10.1080/10502556.2012.682894
Morin, Rich. (October 21, 2013). Is divorce contagious? Pew Research Center. Retrieved from http://www.pewresearch.org/fact-tank/2013/10/21/is-divorce-contagious/
Moutria, Kristen. The Effect of Divorces on Mutual Friendships. Global Post. Retrieved from http://everydaylife.globalpost.com/effects-divorces-mutual-friendships-14139.html