In co-parenting, at least two adults who are not in a romantic relationship find themselves raising their offspring together.
Sexual orientation is secondary in co-parenting. Possible constellations are single people or multi-parent families, where more than two adults take care of the offspring. This can happen when a couple constellation gets together with a single person or another couple. There can be a wide variety of reasons for this. In heterosexual constellations, a person could be unable to procreate or already have children from an emerging relationship and not want any more biological children, or it could be constellations in which people are homosexual or transgender. Rainbow families, where at least one woman and at least one man come together, where at least one person is homosexually oriented, are also co-parenting.