Not a group marriage but two twosomes that were one family, comfortable each with the others.
Some of the original community members believed in the practice of group marriage.
The "group marriage" of the six of them attracts media attention.
A group marriage can be open or closed to outside sexual partners.
But group marriage just wasn't part of our experience up to that point.
Good coverage of the impact of group marriage on children.
A group marriage may be open or closed.
In effect it functioned as a large group marriage until about 1879-1881.
It is also not always visible when people sharing a residence consider themselves privately as a group marriage.
Maybe I should call it a group marriage, because it was that, too.