The parents mentioned drawbacks as well, particularly “the discomfort of having partnerships between adults dissolve and the resulting emotional trauma for children who may have been very attached to a departing partner.”
We have had one relationship that was serious enough and long-lasting enough for the third person to get to know our child. We had a girlfriend and she was part of our family. She and our child got along famously and it was all very comfy and domestic for a time.
But as people do, and as relationships do… change happened. She decided she wanted other things for herself which did not include dating a couple. We went through a sort of bad breakup and unfortunately we were not able to remain friends with her after.
Our child was definitely affected by this, and definitely asked about her. We had to explain that we were no longer friends and that she would not be around anymore. Our child expressed that she was missed. But then, over a few weeks, she seemed to be forgotten.
Our child occasionally brings her up as a concept and expresses that it would be nice if we had a friend like that again.
The kid is more interested in having more people around than who those specific people happen to be. Our child happens to thrive in more of a village setting.
However, just because it seems like a benefit to our family, we absolutely don’t allow interactions between our child and people we are dating unless the relationship reaches a certain level of commitment.
Just like any single parent. We protect our young.